file: pantera/susp.htm
Date: Tue, 09 Dec 1997 02:41:28 +0000
From: JDeRyke {[email protected]} Subject:
Re: Ring Gear/Final Ratio's - Part I
To: Multiple recipients of list {[email protected]}
Dennis, Jr once told me his nearly stock chassis got 'really snakey" at over
180 with gumball tires, which is one reason why he kept on with the Z rated
ones. Can you clarify what he did to finally make the car handle at speed with
gumballs?
Date: Wed, 10 Dec 1997 03:25:43 +0000
From: Dennis Antenucci {[email protected]}
Subject: Re: Ring Gear/Final Ratio's - Part I
To: Multiple recipients of list {[email protected]}
Jack, Junior's handling problems had more to do with the air turbulonce
problem on deaceleration from speeds "above" 180mph then they did with tires.
In fact after he went to his custom spoiler the "really sankey" problems went
away. After blowing out both Pirelli and Yokahoma's he said he never had
another problem with tires once he went to Goodyear Eagles.
He confirmed again today, that "he" believes that the Z rated DOT tires
generate too much heat in an endurance race like Silver State...espially on a
3200 pound Pantera. Add that rear spoiler for added down force and "he"
believes that a race tire is the only tire to drive down the mountain
with....I'm not sure I agree...However,
It is arguable. Pat Mical and Mike Cook agrees with Junior...Dennis Quella,
Gary Hall, Bobby Byers and Frank Zambini all believe The ZR rated DOT tires
with the new 187mph rating will get the job...Another reason I like the DOT
tires is folks have been rained on {REAL not theoretical! :-]} going down the
mountain and gumballs don't handle real well in the wet!! Another
consideration that Dennis Quella pointed out today is the gumballs puncture
more easily. Take your choice!
Date: Tue, 30 Dec 1997 17:39:15 +0000
From: Dennis Antenucci {[email protected]}
Subject: Re: Powder coat wheels/tire options?
To: Multiple recipients of list {[email protected]}
Never let it be said that Cap'n Mike speaks for the Mad Dog...
Mad Dog did, and later discovered his car handled
} better and cornered faster with 15" wheels and BFG R-1 tires, he publicly
} pondered why he ever switched to 17" in the first place...
Well better then MY 17" wheels and tires on MY Pantera!!! In all
fairness I believe "most" folks with 17" tires and wheels will have the same
problem I had during hard cornering at any race track or open road race...the
reality as Keith V. likes to remind us all from time to time is that very few
Pantera's will ever see a race track. I've gotten feedback from two owners who
ran 315/35/17 at track events and had no problem. And John Parson's runs
335/35/17 and 245/35/17 tires, and has had no problem with his Centerline
wheels. I quess a number of things would explain that, starting with our cars
different dimensions! Mike Cook told me that they've found Pantera's with as
much as 1" difference in wheel/tire to body clearance. . .Ahhh the joys of
hand fitted auto's! Check clearances carefully and be prepared to mod to fit.
} The Hoosier Street TD in 275/60 and 245/60 would also be a reasonable option.
I know several people who run these tires both in open track events and
Silver State and they've never had a problem. Eric Petterson, who is the
Silver State Race Tire Consultant told me that in researching tires that did
blow he wasn't able to find one blow-out that wasn't caused by one of the
reasons I mentioned in my POCA story (IE; tire/chassis/body hits, low tire
pressure, etc) and one more thing that wasn't mentioned in the story was folks
running tires that they had previously run in a open track event!!! Which is
why I run new tires at EACH Silver State.
But I fully appreciate that the great majority of Pantera owners aren't going
to road race or open track their cars so I don't see anything wrong with 17"
wheels and tires from a safety standpoint...Jus' remember to check
clearances...and damn Cap'n Mike's design worries. Mad Dog, IRA
Date: Tue, 30 Dec 1997 18:38:44 +0000
From: Cristiano Rossi {[email protected]}
Subject: Chassis stiffening (was powder coat wheels/tire options)
To: Multiple recipients of list {[email protected]}
Jack, your remark about the chassis stiffening leads me to another question:
How do you stiffen the chassis? It can be a good idea also on stock Panteras
to stiffen the chassis because of the spider cracks that some cars can develop
in certain areas due to chassis flexing.
I have read a couple of articles about the subject. As far as I rember, both
articles were published in the POCA magazine.
One article proposed to make a strong welding in the areas where the cracks
occur. I believe that this solution will maybe prevent the cracks, but that it
will not remove the reason for the cracks to occur. So, it will remove the
simptoms, but not cure the problem.
As far as I remember, the other article proposed to custom-make a strong
aluminium block and bolt it somewhere in the engine bay where it will hold
everything together. This sounds to me more like a real solution of the
problem.
If it stiffens the chassis enough and in the right places, my personal
choice would be a third solution: to mount a roll-cage, that will also give
you some other advantages. In an earlier post Mad Dog has confirmed that a
roll cage gives a very good stiffening of the chassis.
How much would the price be for a roll cage, and are there different types
to consider?
And are there other ways of stiffening the chassis that ought to be
considered? And, since many improvements seem to have also some serious
disadvantages, are there any disadvantages of stiffening the chasis?
Date: Wed, 31 Dec 1997 00:04:39 +0000
From: [email protected]
Subject: Re: Re: Chassis stiffening
To: Multiple recipients of list {[email protected]}
Capt Mike Drew
136 Lighthouse Way
Vacaville, CA 95688
Home/FAX: (707) 452-9284
E-mail: [email protected]
Hello all,
Larry Stock got all excited about chassis stiffeners a few years ago. He
went to Roger Krause racing (a very reputable shop here in the Bay Area, and
the local Goodyear race tire rep as well), and had them take all sorts of
measurements, design and fabricate bolt-on chassis stiffeners.
I guess the boys at Krause were able to put the Pantera in a jig and actually
stress the chassis to see where the weak spots are, then design supplemental
bracing to try to deal with it.
When he was done, he had two pieces, one for the front, one for the back.
They looked pretty trick, but I was fairly convinced that they wouldn't be
generic to ALL Panteras-the one for the back in particular was irregularly
shaped, different from side to side, due to variations in the locations of
various suspension pick-up points on the particular car they measured.
The rear one is attached to the car at the forwardmost lower control arm
mounting point, and the forward portion of the brace replaces the chassis
crossmember under the oil pan. I can't remember if the forward piece mounted
in the front trunk, or underneath the car, attached to the chassis. I think
it's underneath though.
Anyway, they ran some skidpad tests with Larry's G-meter. They first tested
the car in 'stock' configuration, and got various results. They then jacked
up the car and attached these braces (wait, I think one had to be welded
on...can't remember now) and then repeated the test. While the ultimate
g-limits had gone up, what was noteworthy was that the curve was much
smoother. The old "sustained lateral g's" graph was all up and down, the car
would rapidly go from .84 or so, up to as high as .93, indicating that the
total available grip was a transitional thing, going up and down, perhaps due
to chassis flexing. With the braces in place, the gap went from .9 down to
3 or so, and I think the overall numbers went up slightly, say, to .91-.94.
The test was shortened by an Incident, however. The owner of the car had
complete several circles in the parking lot, and was driving back over to see
the guys and discuss the results. He wasn't paying attention to where he was
going, and he smashed right into a parking space kerb! He was going about 20
mph and he hit this sucker dead-center (concrete, about six inches high and
three feet wide), and it didn't budge. The Pantera just stopped, BANG!
The whole lower valence was destroyed, of course, and it also took out the
radiator. But the interesting thing is, the rest of the car was COMPLETELY
UNHURT! The chassis reinforcement prevented the load from being transmitted
up to the sheetmetal, or anywhere else. They trailered the car back to the
shop, and the chassis was still straight as an arrow.
So they DO work, apparently. However, they're ridiculously expensive I
think, over $500 each, or is that $1000 each? I can't remember. Larry sort
of lost interest in the project. He had a couple of them made, and they have
sat in his shop ever since, gathering dust.
Somebody might be able to make an offer and steal them out from under him,
because he's making no real effort to sell them, and I don't think he'll EVER
get out of them what he's got into them, $$$-wise.
Date: Wed, 31 Dec 1997 03:34:07 +0000
From: [email protected]
Subject: Fwd: Re: Chassis stiffening [2]
To: Multiple recipients of list {[email protected]}
Whoops! Forgot to send to The List first time...
---------------------
Forwarded message:
Subj: Re: Chassis stiffening [2]
Date: 97-12-31 00:03:10 EST
From: MikeLDrew
To: [email protected]
Capt Mike Drew
136 Lighthouse Way
Vacaville, CA 95688
Home/FAX: (707) 452-9284
E-mail: [email protected]
Cristiano wrote:
}How do you stiffen the chassis? It can be a good idea also on
stock Panteras to stiffen the chassis because of the spider cracks that
some cars can develop in certain areas due to chassis flexing.
}}}I love it when a guy feeds me a straight line. Okay, crack the knuckles,
wiggle the fingers, here we go.
Apparently (according to everything I've read and heard over the years), the
weakest point in the Pantera chassis is just aft of the firewall. Looking at
the car from the side, it's roughly halfway between the back of the door and
the leading edge of the rear fender wheel well.
So, how do you deal with it?
1) Pantera Performance Center (Colorado) sells a Y-shaped pre-formed piece
of sheetmetal, which is designed to be welded in right where the bodyline for
the rear decklid opening makes its sudden turn from near-horizontal and
angles up to the roof. That is where the chassis flex manifests itself the
most, and it's extremely common to see spiderweb cracks emanating from this
point on virtually all Panteras, particularly those that have been driven
hard with slicks or large wheels (i.e. GT5)
(As an aside, another weak spot on the car is where the A-pillar (windshield
post) meets the trailing edge of the front fenders. Typically, hard-driven
cars crack here all the time too.)
These Y-shaped pieces will supposedly stop the BODY from flexing at this
point, and preserve the paint finish. It doesn't deal with the fundamental
underlying problem, just reinforces the weakest point on the surface of the
car and transmits the twisting forces along a greater part of the body.
2) Most people seem to find that a well-designed roll cage does wonders for
chassis stiffness. Specifically, a roll cage that has six points, with four
inside the drivers cabin, and two more points going back to tie in atop the
inner rear wheelhouses. This was the factory solution on the Group 4 cars.
Stress which used to be imparted just to the wheelhouses is now transmitted
through the roll cage to the roof. Much better.
3) Dick Drenske (with his red, white and blue "351" race Pantera) went to
great extremes to prevent chassis flex. He had giant braces made of roll-bar
tubing, they form an "X" in the rear tub. The brace is essentially in the
same plane as the ground (flat), and the tubes run from the corners near the
taillights, up to the leading edge of the inner wheel houses. Come to think
of it, there are two more tubes that go straight out the sides to attach to
the edge of the inner wheel house too. He's got a similar arrangement in the
front trunk area.
When coupled with his full six-point roll cage, I'd expect his car to be as
stiff as can be. In fact, he might have an EIGHT-point cage (two bars going
forward to tie in to the front wheelhouses?)
Dick's efforts to stiffen his chassis can certainly be considered extreme,
and aren't practical at all for a street-driven car.
4) Gary Hall sells a chassis-stiffening kit, for an extremely reasonable
price. Stuff bolts into the front trunk (you can still fit stuff around it,
but you can no longer carry bulky items) and there's some sort of apparatus
in the rear compartment, although it's impossible to make out the photo in
his flyer!
That seems to be the most cost-effective way to go, assuming it works at all.
Due to the poor I can barely see how it's engineered, so I have no way of
guessing.
Date: Wed, 31 Dec 1997 09:27:44 +0000
From: [email protected]
Subject: Re: Chassis stiffening (was powder coat wheels/tire options)
To: Multiple recipients of list {[email protected]}
Chris wrote:
And are there other ways of stiffening the chassis that ought to be
considered? And, since many improvements seem to have also some serio= us
disadvantages, are there any disadvantages of stiffening the chasis?
Cristiano Rossi
thpnma 02869
FWIW, my thoughts:
The Pantera is a monocoque car, a/k/a unibody. There is no distinct =
chassis or frame - or body for that matter. Even the front fenders a=
re welded into the monocoque, unlike most unibody cars. To truly mod=
ify stiffness in a scientific way, you have to perform a finite eleme=
nt analysis of all the ways the structure can flex, such as torsional=
(twist) and longitudinal (bowing). Also, some body flex is not auto=
matically bad. Those familiar with karting know that those little mo=
nsters handle great but have no suspension per se. Like your old Fle=
xible Flyer sled (for those in SoCal it's used in SNOW), the frame tw=
ists and bends, thereby allowing the wheels to move relative to one a=
nother.
A monocoqe can be stiffened very economically in subtle ways that mig=
ht not be intuitively obvious. Even things like a ridge rather than =
flat surface can help. As far as I know, no one has done a scientific=
and quantitative study of the Pantera structure to see where reinfor=
cements will do the most good.
My seat of the pants approach would be to look at my car and survey o=
thers' cars to see where cracks develop. Known places are (1) around=
the bottom outside of the tail lights; (2) around the top of the A-p=
illar; and (3) above the "gills" on the body where the deck lid curve=
s (about 10" behind the hinge point for the deck lid). Reinforce tho=
se places, and not just with a scab weld (it will just make a stress =
riser). I reinforced spot 3, which started cracking after track time=
with R1s, by making an 18 gauge or so three-pronged star thad laid o=
ver the crack and extended flush with the body in the three remaining=
directions and wleding it into the structure to spread the load. If=
you can't envision this, the Pantera Performance Center can make you=
a pair for a nominal charge (actually, they made mine). Punch sever=
al small holes in each reinforcing plate to make welds through to the=
structure. Then grind smooth and do the bodywork to hide the reinfo=
rcements. Cracks here have not returned for me (even aft
As for a roll cage, it does have potential, but I think it is way ove=
rkill for a street car. To really stiffen the car (not just protect =
the occupant), the roll cage should almost certainly tie into the sus=
pension pickup points, and probably other areas as well. That means =
going through the dash and front bulkhead and into the trunk, through=
the rea window and around the engine, and that's just for starters. =
I'd also put tubes in the rocker panels and tie into them as well. =
I just don't see doing this for anything but an all-out race effort. =
BTW, it would have to be welded in place for maximum effect.
Bolt-in stiffening devices are of very limited utility. The bolts (a=
nd holes) carry all of the load, rather than spreading it over welds.=
Also, bolts and holes move a little relative to one another and hav=
e a way of wallowiing out the hole. Finally, most spots to drill hol=
es in a Pantera are pretty thin gauge sheet metal and the holes will =
wallow easily. Things that bolt into areas designed or reinforced to=
take such loads (like the enging bay cross member and suspension pic=
kup points) are fine, but will-nilly drilling is a bad idea. I have =
seen some very fine designs that involve using existing bolts and hol=
es, but don't think this is the entire solution.
As I posted before, who says the Pantera needs stiffening so badly? =
25-year-old car mags when the damn thing was on Arrivas and the struc=
ture wrongly got the blame? I think someone has done a rough measure=
ment of at least torsional rigidity and it ain't that bad. Has anyon=
e compared a Pantera's rigidity in a quantitative sense with cars lik=
e the Mercedes? I'll bet the comparison is not as unfavorable as leg=
end would have us believe. Ask yourself why you think your car needs=
to be stiffened other than someone else saying so before you go off =
the deep end.
Anecdotally, I went off track at about 80 mph in my car (backwards), =
was launched into the air over two tire walls, and had to walk about =
75 yards back to the track to signal others of my mishap. Yes, the c=
ar was slightly bent. My body man with a state-of-the-art frame mach=
ine chewed me out because it took him forever to straighten the car. =
Seems he couldn't get it to budge the normal way by pulling in multi=
ple directions at once. Instead, he had to tie down three corners at=
a time and combine all ot the hydraulic rams on one corner at a time=
in order to straigthen the car. He normally works on Mercedes, BMW,=
Ferrari.
Oh no! It's happening again! I'm starting to turn into Mike (Normy)=
Drew. Not only am I now an expert on everything, I'm starting to li=
ke camels . . .=20
Date: Thu, 01 Jan 1998 17:55:06 +0000
From: JDeRyke {[email protected]}
Subject: Re: Re: Powder coat wheels/tire options?
To: Multiple recipients of list {[email protected]}
FWIW: Larry Stock after a T-bone accident had his Pantera put on Wilkinson's
frame jig. When Larry got it back with a clean bill of health, he bought some
17" wheels. He found that his 17" tire on the left front was flush with the
edge of the fender, while the rt front tire stuck out over an inch from the
fender lip. And this on a recently-verified-straight chassis! Hand-built
bodies, indeed! J DeRyke
Date: Thu, 01 Jan 1998 18:55:57 +0000
From: JDeRyke {[email protected]}
Subject: Re: Re: Chassis stiffening (was powder coat wheels/tire options)
To: Multiple recipients of list {[email protected]}
Thought #2: before you attack your Pantera with a tube-bender & welder, it
might pay to study the chassis design in the back of the orange Parts Book.
Anecdote: at the San Diego Vintage races a few years back, a race-modified
Austin Mini (another monococque design) tipped onto it's side at high speed
(for a Mini, anyway) while entering a turn. Sliding, the car directly impacted
a guardrail with it's top. The full roll cage punched through the floor
mountings, slid down like a nutmeat mincer and killed the driver. Reportedly,
over a foot of roll bar legs were protruding from the underside of the car! In
retrospect, the floor mountings weren't of large enough surface area, and the
underlying floor area was very rusty but wasn't inspected. Don't know if the
cage was welded in or not. J DeRyke
Date: Thu, 01 Jan 1998 19:28:13 +0000
From: JDeRyke {[email protected]}
Subject: Re: Sway Bar
To: Multiple recipients of list {[email protected]}
The stock rear bar is 0.815" dia; the best replacement for most Panteras is
the so-called GTS bar, which is 0.875" dia, or about twice as stiff (bar
stiffness increases as the square of the dia increase). This painted bar was
sold by the Factory for use with 10" wheels and for 'vigorous driving'. Some
are available used from time to time. Chrome plating must be baked out afte
plating since high-carbon steel absorbs hydrogen during plating, then cracks;
be careful of 'home-made' shiny chassis stuff. The stock front bar is also
0.815 but the leverage is different so it's stiffer than the 0.875 rear bar.
It's probably fine as is. J DeRyke
Date: Thu, 01 Jan 1998 19:49:47 +0000
From: JDeRyke {[email protected]}
Subject: Re: Sway Bars
To: Multiple recipients of list {[email protected]}
During our Solo 2 days, we tried removing the front bar. The car heeled over
in hard turns like a mid-'60s Buick! We finally went to a custom 5/8" front
bar & a GTS rear bar, mounted in J C Whitney urethane bushings. With Yokohama
225-50x 15 frt & Hoosier 275-50x 15 rears, the car was absolutely NAILED to
the track! 'Course, we ate a set of rear tires in less than1000 miles....
nothing's ever free! J DeRyke
Date: Thu, 01 Jan 1998 22:39:50 +0000
From: Dennis Antenucci {[email protected]}
Subject: Re: Powder coat wheels/tire options?
To: Multiple recipients of list {[email protected]}
Yo Jack & Others Interested,
I have also noticed the wheels/tires on "some" aftermarket wheels that
stuck outside the fender and the owners told me they had never had any
structual damage. One thing is for sure...There is a deminishing supply
and choice of tires for our beloved 15" Campy wheels. All the more reason
to watch over them anytime they go to a tire store to ensure their not
mistreated or over/under torqued.
Bo Bo is trying to sort out some wheel/tire options for his Pantera and
Cap'n Mike suggested that perhaps he was trying to save 5% over the
vendors prices. . .He added big smiles of course because he knew Bo Bo
could break him in two quicker then a gorilla can break a Campy wheel by
over torquing! [BIG GRIN]
To be honest with you there's alot of wheel selections out there to
choose from but nothing even close to the Campy's...except the Wilkinson
wheel, which is beautiful if not pricy. I think one of the basic
misconceptions I had when I bought my aftermarket wheels and tires was,
"wider is better". I now know from experience that isn't always true.
Having learned that hard earned $$$ lesson...I am surprised vendors
aren't yet making 18-20" wheels to fit all the tire/wheel combinations
I've seen in tire Rack ads (IE 295/35/18, 275/35/20, etc). Andy, Kirby
and you other tire experts out there care to comment on these taller
tires and wheels???
Date: Thu, 01 Jan 1998 23:39:20 +0000
From: DtomasoCat {[email protected]}
Subject: Re: Collapsable spare and inflation
To: Multiple recipients of list {[email protected]}
The collapsable wheel/tire combination in a stock early '70's Pantera was
identical to the ones used in the '71-'73 Mustangs. It was a BF Goodrich
"Space saver" spare. You could fill it up with the can of air supplied with
the car or use an air compressor to inflate it. The problem was that people
didn't read the instructions fully (who ever does, really?) and they would
inflate that puppy like a balloon. Then "BLAM!" it would explode and take a
persons limb off.
I was a judge for the Mustang Club of America in the 1969-70 and 1971-1973
classes and it was really rare to find a perfect unused space saver spare and
even rarer yet to find the original can of Ford "air" with it. It was always
a little difficult to figure out if the ford air was still in the can or not.
Most of the time we just took their word for it.
By the way, those space saver spares in mint unused condition could easily
cost $250 or more. The Mustang guys couldn't get enough of them. An original
can of air for the spare in mint condion could run you $200 or more to boot!
Date: Fri, 02 Jan 1998 19:03:09 +0000
From: JDeRyke {[email protected]}
Subject: Re: Re[3]: Self Cancel turn signals
To: Multiple recipients of list {[email protected]}
Biggest problem with the Pantera's handling is, you cannot cram enough front
tire under the stock fenders to overcome the built-in understeer that Ford
designed for us. Also, a tight posi differential will cause even more
understeer. Try a smaller-than-stock front swaybar (we used 0.625 dia; stock
is 0.815), a GTS (.875 dia.) rear bar, 245-50 x 15" front tires and no wider
than 275-50 x 15" rears. This will get most street Panteras closer to neutral
handling, but remember, understeer is idiot-proof: when it slides, back off
the gas and thinks are OK. Oversteer is dangerous: when it slides, don't move
the gas at all or you'll spin! Neutral handling is really ragged-edge
handling. J DeRyke
Date: Sat, 03 Jan 1998 15:39:00 +0000
From: JDeRyke {[email protected]}
Subject: Re: Re: Collapsable spare and inflation
To: Multiple recipients of list {[email protected]}
Uh-uh. The Pantera spare was a plain-vanilla 14 x 6" steel Ford wheel with a
BFG folded-sidewall tire. Most original tires were recalled due to a tendency
to blow out. I'd say, any folded-sidewall spare needs yearly inspections for
ozone cracking. Ted, help us out here! I've forgotten the history.
I've converted Porsche 16 x 5" alloy wheels w/folded spare to Pantera bolt
pattern, and the before-mentioned hi-pressure 18" Mustang skinny-spare on a
4-bolt forged aluminum wheel, both of which will clear big aftermarket brakes.
The 18" won't fit in the frt trunk, though. J DeRyke
Date: Sat, 03 Jan 1998 15:40:03 +0000
From: JDeRyke {[email protected]}
Subject: Re: sway bars
To: Multiple recipients of list {[email protected]}
The Pantera's front swaybar is rigged with shorter arms /different leverage
than the rear, thus it is stiffer than the rear bar. Rule of thumb: for
'problems' on the front end, work with the bar on the rear & vice-versa. The
Pantera suspension was redesigned by Fomoco at the last minute due to concern
over whether the gen public was competent to handle a neutral-steering mid-
engine car with power. In hindsight, I'd say they were right... By going to a
small front bar, the rear will tend more toward oversteer, balencing the
designed-in understeer. You could go with an even stiffer rear bar & leave the
front alone except that an unbraced Pantera cannot handle much more than the
GTS bar in back. The stock chassis seems to flex with stiffer rear bars. The
5/8" front/7/8" rear combination worked for us, anyway. J DeRyke
Date: Sat, 03 Jan 1998 23:47:07 +0000
From: JDeRyke {[email protected]}
Subject: Re: Re: sway bars
To: Multiple recipients of list {[email protected]}
I think it's difficult to deal with the "front" or the "rear" of a true
monococque chassis, since it's really all the same single piece. What we've
got with our Pantera chassis is a fairly stiff box with a gigantic hole cut
into its top where the trunk lid goes, and three smaller holes where the doors
& front hood go. Anything you can do to stiffen up the chassis will be minor
until you deal with those holes in the structure. It affects both front & rear
suspensions, possibly the rear a bit more. To put it another way, take a Ritz
cracker box and cut four proportionally sized holes in the sides & top like a
Pantera's chassis. Stiffening up the remainder of the box ain't gonna do much
until you attack the root cause of the flex- the big holes. J DeRyke
Date: Tue, 06 Jan 1998 00:33:20 +0000
From: [email protected]
Subject: Sway Bars [part 2]
To: Multiple recipients of list {[email protected]}
Well, the List barfed back this article I posted last night, saying it's too
long! So now I'm sending it as parts 2 and 3.
This thing is only two pages long-Andy, what gives?
-----------------
The Shade-Tree Mechanic
Swaybars: What's Right for the Pantera?
By Jack DeRyke and Mike Drew
What is a sway-bar, really? A swaybar is a piece of steel barstock that
connects the suspension together on opposite sides of a car that has
independent suspension. The bar can be on either the front or rear
suspension. Fastened between the left and right side suspension pieces, the
bar acts as a twisted torsion-bar when one of the wheels hits a bump or the
vehicle leans in a corner. The spring-force of one bar end twisting up tends
to force up the opposite side wheel, which is being extended by the body
rolling away from it. In this way, the suspensions for the two sides of the
car are "evened out" as far as the forces acting on them, but more
importantly, the "light side" wheel is forced up while the car body is forcing
it down.
This adds cornering force to the (relatively) lightly-loaded inside wheel and
removes some of that same force from the heavily-loaded outside wheel. It
also tends to keep the wheels and tires more straight-up-and-down so the
tire's traction-footprint is maximized. Too, the reaction force from the bar
to the body of the car will affect the "lean angle" of the body, which affects
the driver's perception of how things are going down under him, as well as
preventing the tires from tipping over onto their low traction sidewall areas.
A drastically-tilted body and driver's seat, together with reduced tire
traction, is not a confidence-builder for speeding up your cornering!
A high-performance car like the Pantera has anti-sway bars at both ends of the
car. There is a relationship between the two bars that affects the cornering,
called "roll distribution". Increasing the front roll stiffness loads the
outside front tire and unloads the inside rear tire. This tends to cause
understeer by increasing the front-tire "slip angle". This is done by
increasing the stiffness of the front anti-sway bar. Conversely, increasing
the stiffness of the rear bar will unload the front tire, increase the load on
the rear tire and the car will "oversteer". Understeer is when the steering
wheel has no effect on the direction of the car, which goes off the outside of
a turn. Oversteer occurs when the rear attempts to pass the front in a turn,
and the car goes off backwards. It has been described thusly: "Understeer is
when you see what you're gonna hit, while with oversteer you don't."
Mid-engine cars are often designed to be neutral, neither over- nor under-
steering. Unfortunately for those with racing aspirations, when Ford became
involved with the Pantera, they redesigned the front suspension for
understeer. Understeer is what nearly all street cars have straight from the
factory, because it's self-correcting: if you find yourself too fast in a
corner, slow down a bit and the steering works okay again. But what they did
not design out is another characteristic of mid-engine cars: ultra-quick
steering response. Because the main mass of the car is very near the center
of balance, things happen extremely fast in a mid-engined auto when one end or
the other begins sliding. My experience in autocrossing Panteras leads me to
say that, if the front or rear tires break loose in a turn, it's very
difficult to catch the car without what a one writer called "a lot of untidy
elbow-flailing from the driver". Both the Porsche 928 and 944 were designed
from a "clean sheet of paper", but this "twitchiness" led the Germans to
design them both with the main masses at each end rather than concentrated in
the middle, just to slow down their handling for the benefit of the average
driver.
A complicating factor in this balancing act between front and rear bar
stiffness, front and rear tire sizes and steering response time, is the
limited-slip differential. The tighter your "posi" unit is, the more tendency
there is for oversteer, because the rear axle acts like it has no
differential, or like what dirt-track guys called a "Lincoln-locker", from
their practice of using a (Lincoln) arc-welder to weld the spider gears
together for racing. This is particularly troublesome because the degree of
"lock" from a posi-unit changes with gear lube temperature, confusing your
diagnosis of handling woes. A quick check of the amount of traction one gets
from a limited-slip: GM's test is to wet down the concrete under one tire,
then lay a two-by-four in front of the other wheel. If the rear wheel can
barely climb the two-by-four, a brand-new limited-slip is set just right! But,
by this time in our 20-plus-year-old Panteras, we probably don't have to worry
about the posi being too tight!
OK, so what's the effect of changing swaybar sizes a bit? A stock Pantera has
a .750" bar in the rear and a .845" one in the front; the lever arm on the
front bar is shorter, so it is stiffer-acting than the longer rear as well.
When 10" rear wheels are mounted, the factory recommended increasing the rear
bar to .875". That 1/8" increase raised the bar stiffness by roughly 50%. A
1" rear bar would be 3.15X stiffer. When Rich Agiorni and I autocrossed his
'71 back in the '80s, we ran a 1-1/8" rear bar and decreased the front to
.675"! For autocross/solo-II's fairly low-speed turns, this worked great.
The hollow bars we used were 5% less stiff than solid bars would be, but 40%
lighter! I'm not sure what the car would've done with this chassis setup at
real high speeds, either. I suspect it might've been a real handful, though,
because it was so super-quick-handling in turns! Interestingly, a noted
midwestern Pantera owner has terrific success autocrossing his car with a
stock rear bar and no front bar at all!
[continued in part 3]
Date: Tue, 06 Jan 1998 00:33:54 +0000
From: [email protected]
Subject: Sway Bars [part 3]
To: Multiple recipients of list {[email protected]}
[The third and final part of this discussion]
Larry Stock had a new motor built after losing the mostly-stock original at
Las Vegas '92 to a spun rod bearing. We think this occurred due to Larry
using Goodyear race slicks with a stock oiling system. The new motor is
substantially stronger than before, so he really wanted to maximize the
handling of his now not-so-stock Pantera. A 100-ft diameter skidpad was laid
out in a lot across from his business. The surface was an average asphalt-
bonded stone, about five years old. A G-analyst from Valentine Research was
solidly mounted in his car per directions, on the console back in the knick-
knack tray. This position seemed to be very close to the center of balance of
the car. The good folks at Pantera Performance Center in Denver, Colorado,
provided a variety of swaybars for us to test and compare.
The car is a '72 Pantera, with stock suspension components except for Carello
shocks, running 15x8 front and 15x10 rear aftermarket wheels with Pirelli P7's
in the standard 225/50-15 and 285-50/15 sizes. The wheels had stock offset
and required no flares or spacers to fit. The shocks were adjustable, but
were not optimized for the various swaybar combinations used. To obtain the
best handling characteristics, the ride was lowered, and the front end was set
for 1/8" toe-out and -1.5x camber.
In Test 1, the car used stock front and rear swaybars; 0.845" front, .750
rear. It was able to maintain 0.79 g's on the described skidpad.
Test 2: the rear bar was exchanged for a .875" unit. This is the so-called
GTS or Group 3 swaybar setup, recommended when running larger-than-stock rear
wheels/tires. The car was now able to maintain 0.93 g's with this single
change. Since the bar change took over half an hour, the tires had obviously
cooled back down to ambient before starting Test 2.
Test 3: figuring that if some is good, more is better, the front bar was
exchanged for a 1.0" bar, while the rear stayed at .875". Now, the car could
only hold 0.91 g's - a slight step backwards from Test 2.
Test 4: the rear bar was increased to 1.0" along with the 1.0" front bar from
Test 3. The car could only hold 0.89 g's while in this configuration, a
further step backwards. This is especially confusing, since it is the
configuration used by some for road racing, and was recommended by the folks
at Pantera Performance as the "killer setup". However, they have used this
combination mostly on cars with 15x10 front and 15x13 rear wheels, i.e. Group
4 or GT-5 cars, which not only have much more rubber on the ground, but
possess a much wider track, as well.
For Test 5, the car was returned to the test 2 configuration and Larry's
favorite gumball race tires were mounted. In studying the printouts from the
G-analyst for this Test, it can be seen that the car now turns left at 1.10
g's and turns right at 1.25 g's. Left turns are smooth and predictable while
the right turn segment was ragged and obviously right on (or over) the edge.
With cornering power like this, it is easy to see why Larry had oiling
problems on the racetrack. The oil in the stock pan rode right up the side,
away from the pump pickup. After a few episodes of the pump sucking air,
there were no bearings left!
Most people can turn to the left faster than to the right, simply because in a
hard left turn, the whole car is pivoting around the driver's seat. During
right turns, the driver's position is also pivoting with the car, so his point
of reference is constantly changing during the turn. This introduces another
variable or two which destabilizes the driver's reference points. The result
is, you tend to slow down (unless you are in a 'banzai' mode, but this is
difficult to maintain for long, and often results in a trip to the tules).
So why didn't the progressivly stiffer bars give progressivly better
performance? The answer probably lies not with the swaybar or suspension, but
with the chassis itself. Noted engineer Kevin Cameron recently wrote a piece
on the relationships between frame and suspension stiffness in motorcycles,
and used automobiles to explain his theories. He described the fact that any
suspension is three springs in series - first is the tire, deflecting to
absorb the smallest bumps; next is the suspension spring and associated
components; behind that is the flexibility of the chassis itself, being
deflected by the forces transmitted through the suspension.
Stock car racers learned years ago that there is no point in putting stiffer
suspension on a chassis too weak to support it. As a bump pushes the wheel
up, the spring, shock absorber and sway bar resist the motion, passing on the
force to that corner of the vehicle, which bends upward as well. Once the
bump has passed, the shock absorber prevents the wheel from snapping back,
rebounding off the pavement again, and continuing to oscillate. But the
chassis has no shock absorber to damp its motion so it continues to vibrate up
and down. This continuing motion can be just as disturbing to tire grip as
running without a shock absorber. The correct response would be to stiffen
the chassis (notoriously weak in the Pantera, particularly in the rear,
although extrordinarily strong by street-car standards), to force more of the
bending to occur in the suspension, less in the chassis. However, this would
require major re-engineering of the chassis, and the costs of the design and
fabrication would be prohibitive to all but the most die-hard Pantera crazies.
It seems that most Pantera owners would be well-served by changing their rear
bar to a .875" unit and leaving the front bar alone, particularly if the
tires have been upgraded to at least 1980's-spec sizes. Besides increasing
the overall cornering abilities of the car, the driving characteristics will
likely become much more neutral, without the plowing of the front end that
Pantera owners have endured for decades. However, such a setup will create
the need for circumspection when driving, for once the car reaches its
(higher) limit, it will probably be much less forgiving!
--------------
Note: This data was collected in 1993, but the thoughts behind it are sound.
I realize that serious chassis gurus like Gary with his super-sexy data
acquisition devices, etc. might be able to improve on these thoughts, or view
them as an oversimplification of an admittedly dynamic situation. But for
95% of us, this here about covers it! :})
Date: Tue, 06 Jan 1998 01:42:33 +0000
From: Andy Poling {[email protected]}
Subject: Re: Spreader bar
To: Multiple recipients of list {[email protected]}
You know, this brings up something I've been meaning to ask...
Has any body ever actually determined for certain that the load on the
spreader bar is inward (comrpession) during cornering?
That may sound like an idiotic question, and you may be wondering if I've
taken leave of my sanity, but let me explain why I ask before you dismiss
the possibility.
I read recently that one of the strut tower brace makers for P-cars
(CamberMeister) did some instrumented testing and determined that the
loading imposed by hard cornering on the tops of the strut towers in the 911
and 944 are actually *outward* rather than inward as previously believed.
Their explanation involved considering that the heavily loaded outside wheel
is loaded inward (toward the center of the car) at the contact patch, and if
the lower suspension anchor is fixed, that translates to an outward load at
the top of the wheel, spindle and strut. So they redesigned their strut
tower braces to resist expansion instead of compression.
Now, I realize that our double A-arm suspension is a pretty distant cousin
to a strut suspension, but if you draw a force vector for the cornering
force it does indeed appear to lever the upper A-arm outward (with the lower
A-arm as the pivot point) on the outside wheel.
Am I over-simplifying, or might there be a kernel of truth here?
I remember somebody (the memory is fuzzy... Ron Sickle maybe?) designed a
pretty unusual lightweight shear force brace that was concerned with
distributing braking force (forward on the upper A-arm as I recall, and thus
inward at the front of the wheelhouse) over a wider area, using 4 mounting
points. But I don't recall that he specifically addressed cornering forces
in his design or the article (which I think was in a PI back-issue).
Date: Tue, 06 Jan 1998 15:17:05 +0000
From: Mike Trusty {[email protected]}
Subject: Spreader Bar
To: Multiple recipients of list {[email protected]}
Two points about this device have been asked:
Chuck wrote:
Is there a dimension/measurement that the bar should be set to. Or more
clearly, how wide (long ?) is the bar when correctly set
Andy wrote:
Has any body ever actually determined for certain that the load on the
spreader bar is inward (compression) during cornering?
Listed below are my opinions on these questions.
1. Mike Drew is right about the slotted holes being all wrong.
2. It would be impossible to answer Chuck's question with a dimension.
3. The reason that the after market units are adjustable are to allow you
to extend them out until they bottom on each side of the slots.
4. The method to mount the spreader bar would apply to both the original
and after market units.
a. Place a jack under the back of the car and raise the car only enough to
take the weight off of the rear suspension.
b. Remove the spreader bar and associated hardware.
c. Clean the outsides of the slotted flanges on the tube to bare metal
ready to accept welding.
d. Replace the spreader bar with the addition of large diameter thick
machine grade washers with the same inside diameter ad the securing bolts.
These four washers go on the outside of the flanges mentioned above.
e. With a MIG or TIG welder, tack the washers to the flange tabs.
f. After refinishing these areas, install the spreader bar and tighten bolts.
g. Lower car.
5. Again this, in my opinion, should be done if you are using the stock or
after market bars.
6. The other reason for the welded in washer is to address the problem that
Andy pointed out. Even if it were not an actual tension load it is most
likely somewhat of a lesser compression load at certain times. The result
is the same. This would most likely happen at the initial turn in to a
corner.
7. Jacking of the car is simply trying to locate the mid point in the
chassis flex to mount the bar.
8. The worst mistake I have seen some do is to actually jack a load into
the chassis with the after market bars. Big Mistake.
9. With this method the after market bars are really for:
a. Adding weight to the vehicle.
b. Looking good.(This is why I have one)
c. Meeting one's annual expenditure budget.
Date: Tue, 06 Jan 1998 19:15:08 +0000
From: Craig Cline {[email protected]}
Subject: Re: Wheels
To: Multiple recipients of list {[email protected]}
I know this is a rather late reply, but I'm still playing catch up from being
off for the holidays, I've got 280 messages waiting to read.
I had to measure my set of stock Campis when I put them unto my 1969 Mustang.
The following are the measurements I made (all to the nearest 1/8").
The 7" wheels have 3 5/8" backspacing (1/8" positive offset).
The 8" wheels have 4 5/8" backspacing (5/8" positive offset).
I don't know for certain about the 10" Campi's, I've never had any, but I
would guess that they would have the same backspacing as the 8" wheels (4 5/8"
backspacing or 3/8" negative offset).
As previously stated in other posts, the Pantera uses a standard
Ford bolt pattern of 5 on 4.5".
Date: Wed, 07 Jan 1998 15:33:53 +0000
From: JDeRyke {[email protected]}
Subject: Re: Re: Re- Collapsable spare
To: Multiple recipients of list {[email protected]}
Correction- the 18" skinny-spare WILL fit some Panteras up front. But your car
must have the clutch master hard line 'massaged' a bit, and the power brake
booster vacuum line connection must be on the fenderwell side of the booster.
Most Panteras have the big vac line connection near the clutch master, but not
all. The vac. connection is on a boss on the booster that interferes. Fitting
the 18" spare in is tight, obviously! J DeRyke
Date: Wed, 14 Jan 1998 21:22:40 +0000
From: Dennis Antenucci {[email protected]}
Subject: Suspension/Alignment Settings
To: Multiple recipients of list {[email protected]}
Mike Anderson who is planning to go faster at the Silver Open Road asked
me about what alignment settings I used road racing and was it any
different then what I used for open track at Willow Springs...I used
Jack's recommendations and with the exception of bump steer adjustments
and adding the caster adjustments I haven't found any need to change the
settings...and their race proven...I still have some question on adding
stiffer springs but that's a subject for another post...
What ever you decide to do be sure you carefully realign your suspension.
after making any changes and that includes ride height. Here's the
settings:
Caster: I run 6 degrees positive (get all you can)
2 degrees positive is outstanding for a street
car.
Camber: 1 degree negative
front & rear (if possilbe use camber lock kit)
Toe: 1/16" inch front & rear (as much as 1/32)
Tire Pressures: 32-36 psi front/36-40 psi rear (Street)
40-42 psi front/42-44 psi rear (Silver State)
I revisited the archives and this is what I shared with Mike A. and may be of
interest to anyone else working on their suspension/alignment this winter...
Cap'n Mike likes to ride behind a Pantera (cause he can't drive his!) and
estimate the parallelism of the rear lower A-arms to the pavement. Most cars,
Mike says are not equal side to side. The natural collapse of the rear
suspension points on many of our cars probably has dialed in about as much or
more negative camber then you need, so an effort should be made to balance the
two sides of the car's rear suspension.
Camber angle is the amount the top of the tire is leaned inboard (negative) or
outboard (positive). The wider and lower profile your tires are, the less
camber angle change you can tolerate. As the tires lean, the edge will pick up
off the road, resuulting in a sudden and drastic change in adhesion of that
tire. We can't eliminate camber changes, although late-model longer A-arms
would minimize it. But we can adjust our wheel alignment such that in
cornering, positve camber on the inside wheel does not happen. This is
normally done by setting the static camber to a negative value so that when
you rip into a turn at high speed, body lean will not be able to tip the
heavily loaded inside wheel into positive camber and surprise you into the
tulles. Negative camber will naturally wear the "outside" edges of the tires
rapidly, so lots of negative camber on the street is only for as I once
described it, "those slowly dying of testosterone poisoning" or the owners of
tire companies!
Everyone knows about toe adjustment right? The steering rods are shortened or
lengthened to pull the front edge of the tires inboard or outboard. Lots of
toe angle promotes high speed stability, up to a point. Most cars of the 70's
run a standard 1/8" inch of positive toe. High performance cars (like mine)
with stiff suspension bushings run as little toe as possible for decreased
tire drag 1/16" inch or even 1/32" inch. for low speed autocross competition,
one can use front toe-out to take advantage of the very sharp corner-entry
behavior this will allow. (Comments Andy?)
But above about 50 mph, the car will begin to wander; the faster you go, the
worse it will get. Those bikers who have lived through a speed-wobble or
tankslapper as they are called, will recognize where we are headed with toe-
out. And NEVER under any circumstances run any toe-out in the rear. It is a
recipe for disaster at speed.
You may find like I did that dialing anything more then 2 degrees positve
caster is the maximum you can get on a stock car. To then increase the postive
caster you can then opt for adjustable upper A-Arms like the vendors sell or
have your own upper A-arms machined and adding a shim-pack for more adjustment
range. Both sides should be as close to equal as possible.
Bump steer is another condition that affects cornering on all but pool-table
smooth roads (kinna like Pocono!). The tire and wheel attach to the spindle
and the spindle is steered by rods that are anchored to the steering rack on
one end and ball-adjusted to the spindle steering arms on the the other. When
a tire hits a bump, the whole assembly rises. But the rack end of the steering
rod doesn't move. So the steering rod moves through an arc instead of a
straight line. The tire is also anchored at the inboard ends of the A-arms and
moves through an arc. But the arcs from the A-arms and steering rods don't
match. The geometry is such that toe-in changes, and the driver feels this as
a darting movement which can be very unsettling, depending on the speed
involved. Before I modified my suspension and alignment I've found it to be
most pronounced at high speeds on roads like Silver State where your exceeding
the triple nickel! :-]
To minimize a Pantera's bump-steer (it cannot be truly eliminated), the
steering rod heights will have to be changed relative to the spindle. this can
be done by lowering the steering rack or by raising the rod ball-joints. While
the amount needed will be different for every car and should be measured
before changing it, some Pantera parts suppliers have checked enough cars to
make a good quess at how much spacing your car will need to improve and
minimize bumpsteer. To install the kit, the tapered hole in the steering arms
must be drilled out to a straight hole. Then, a spacer with a protruding shank
is put on top of the steering arm and tie-rod ball stud is pushed through the
spacer and into the drilled-out steering arm. There was a product "Safety
Alert" in the Feb '96 POCA Newsletter which Jack went into detail describing
how a loose protruding-shank nut (since safety wired) galled or seized then
came loose. This problem started when "SOME" steering arms were drilled out
from the stock taper to a slightly larger straight hole. What probably occured
was ordinary drill bits do NOT make round holes; instead, the hole that
results is faintly triangular, the amount depending on the drill point angle
and the cutting speed, feed rate, material toughness, etc. Or it may have been
simply a case of a worn drill which will cut an udersized hole. In any case if
you didn't see Jack's Safety Alert earlier you may want to carefully inspect
your tapered balljoint stud, bump steer spacer, steering arm and the
protruding-shank nut which should be safety
{{{}}}
you have anything to add??
Besides Jack, I'm sure others have some experience they would also like to add
so please add your two cents worth on a very importent safety issue.
Mad Dog, IRA
The spindle is mounted not perfectly upright but laid back towards the
windshield abit. The angle it is laid back is the caster angle, More caster
angle results in high speed stability but with more effort in steering at low
speed. This is because when the wheels are turned, you are physically lifting
the weight of the front of the car a fraction of an inch, suing only the
steering wheel for leverage. Note that adjusting caster will ALSO change bump
steer and toe. . .Remember, everything is interconnected.
Date: Thu, 15 Jan 1998 01:18:51 +0000
From: [email protected]
Subject: Re: Suspension/Alignment Settings
To: Multiple recipients of list {[email protected]}
Great piece, but I think you propagated a simple error JD first put forth in a
POCA piece, which HE perhaps got (?) from a simple error in 'How To Make Your
Car Handle?' I'm going out on a limb here, but reason with me. You wrote:
}But we can adjust our wheel alignment such that in cornering, positve camber
}on the inside wheel does not happen.
}}}Sounds good so far...
}This is normally done by setting the static camber
to a negative value
}}}right, right...
}so that when you rip into a turn at high speed, body
lean will not be able to tip the heavily loaded inside wheel
}}}Whoop! Whoop! Since when is the INSIDE wheel the heavily loaded wheel in
a turn? That's why we have sway bars, to transfer some of the load from the
outside to the inside wheel, right?
}into positive camber
}}}...and why would the inside wheel go into positive camber? Save for
certain swing-axle cars like VW Bugs, the front suspension on Allards, etc..
When cornering, centripital force tries to push the body of the car towards
the outside of the corner. All things being equal, this causes the tops of
both tires to lean towards the outside of the corner, right? That's NEGATIVE
camber on the inside wheel then, POSITIVE on the outside.
}and surprise you into the tulles. Negative camber will
naturally wear the "outside" edges of the tires rapidly,
}}}Whoop! Whoop! Wait a minute, negative camber is when the tops of the
tires are tilted inwards. Taken to an extreme, the outside edge of the tire
doesn't even touch the ground! On Panteras, with negative camber in the
rear, the INSIDE of the tire wears before the outside. Similarly, on my
GT-350 with race-car spec alignment (about 1 1/2 or 2 degrees negative in
front), I'm getting big-time tire wear on the inside edge (and poor braking
performance 'cause the tire isn't flat on the road; I'm going to go back to
0.5 to 1 degree negative here soon.)
}so lots of negative camber on the street is only for as I once described it,
}"those slowly dying of testosterone poisoning" or the owners of tire
}companies!
}}}True enough!
You also wrote:
}Cap'n Mike likes to ride behind a Pantera (cause he can't drive his!) and
estimate the parallelism of the rear lower A-arms to the pavement. Most
cars, Mike says are not equal side to side.
}}}Most are pretty close, actually, but some aren't. This can be caused by
several things. You put a monster like Bo-Bo or Crash Jim in a car with a
full tank of gas, no passenger, and then drive it for 30 years, and the left
side springs sack out and the car tilts to the left. Check out the brown and
black Pantera Showcar (Group 4 car) featured in the Rasumssen book "Panteras
For The Road"; about 2/3 through the book (no page numbers!); one shot from
the direct rear shows the left side sagging quite a bit, probably for this
reason. If I had a car like that, first thing I'd do is swap everything from
one side to the other and see what happened. Hell, you'd probably get
another 30 years in!
Such sagging can also be attributed to Bad Things. I once followed Jack
DeRyke's car home from Las Vegas and realized that his chassis is big-time
bent. The body sits nice and flush, flat to the ground, but the left-side
swaybar mount is about 3/4 of an inch higher off the ground than the
right-side one! The left a-arm rises up from the bottom of the hub to meet
the chassis; the right a-arm drops quite a bit from the hub to the chassis,
yet the body is square. Scary! (His car was whacked sometime in its life;
the radiator sits crooked in the car too!)
}The natural collapse of the rear suspension points on many of our cars
}probably has dialed in about as much or more negative camber then you need,
}so an effort should be made to balance the two sides of the car's rear
}suspension.
}}}But NOT by cramming a bloody great aluminum spreader bar in and cranking
in the torque. Set the thing up so it's firm, then use adjustable a-arms if
you still have too much negative camber.
So anyway, am I full of hot air on this, or what?
Date: Thu, 15 Jan 1998 22:53:29 +0000
From: [email protected]
Subject: Front Spindle Answers, and questions!
To: Multiple recipients of list {[email protected]}
The thread Chuck started on spindles got me thinking, so I did some homework.
Turns out there were THREE different types of front spindles. The spindle
assembly is actually two pieces.
Type 1 consisted of a three-armed spindle support (top and bottom arms go to
the ball joints, middle arm goes to the tie rod), with a threaded spindle
shaft. This was the early style Jack had earlier referred to, with the nut
requiring hammering, etc. etc.
Type 2 consists of a two-armed spindle ass'y (top and bottom arms go to the
ball joints, and the spindle shaft is integral with the unit) and a bolt-on
third arm which goes to the tie rod.
Type 3 is the GT5 unit; presumably the same design as Type 2 except perhaps
beefier.
Chuck has the Type 2 unit, with the castellated nut. According to the
orange-cover Ford factory parts book (which, occasionally, is actually worth
a damn), the changeover from type 1 to type 2 took place with car
THPNMD04099, July '72.
Undoubtedly, the design change was made to reduce costs; the early style
requires two complicated mirror-image spindles; the late style uses the same
spindles on both sides, with a smaller, cheaper, mirror-image pair of bolt-on
arms to attach to the steering rack.
But. The Ford parts book lists the different parts numbers for both Type 1
spindle shafts and associated nuts, leading me to believe that one spindle
shaft is LH thread and the other RH. The book lists only one part number for
the Type 2 spindle (including nut), but two part numbers for LH and RH
spindle nuts-leading me to wonder what the hell is going on.
Nuts! Chuck, since you've got type 2 and have been playing recently, can you
tell us if the nuts are interchangeable?
Date: Fri, 16 Jan 1998 00:05:49 +0000
From: David Doddek {[email protected]}
Subject: Re: Front Spindle Answers, and questions!
To: Multiple recipients of list {[email protected]}
}But. The Ford parts book lists the different parts numbers for both Type 1
}spindle shafts and associated nuts, leading me to believe that one spindle
}shaft is LH thread and the other RH. The book lists only one part number for
}the Type 2 spindle (including nut), but two part numbers for LH and RH
}spindle nuts-leading me to wonder what the hell is going on. Nuts! Chuck,
}since you've got type 2 and have been playing recently, can you tell us if
}the nuts are interchangeable?
Well Mike, I am not Chuck, but I have changed front wheel bearings before and
I can tell you that both the right and left side of my Type 2 spindles both
have right hand thread nuts that appear to be identical. By the way, the
bearings in the front of the pantera are VERY common types and can be bought
at any bearing supplier. In fact, the outer one is the same that is used in
our boat trailer, only costs about $5. I even matched up the seal with one in
the Chicago Rawhide catalog so I did not have to get one that was special.
Also, a light grey appearance on the bearing rollers our outer race is ok, but
any blue or dark grey color indicates over temp and the bearing and race
should be replaced. Also after replacing the front bearings, recheck the
adjustment for play after about 500 miles. Some times the races tend to move
a little and make the bearings a little loose. Loose bearings will overheat
from missalignment. Proper preload of the bearings is difficult to measure,
but use the following procedure to set.
--Tighten spindle nut to about 20 ft-lbs while rotating the wheel.
--Loosen the nut until finger loose.
--tighten the nut finger tight and rotate to the next available slot in the
castle nut an insert cotterpin.
-- wheel should rotate freely with little effort
--Road test car at highway speeds, stop and feel hub for abnormal
temperatures.
Date: Fri, 16 Jan 1998 00:07:20 +0000
From: DtomasoCat {[email protected]}
Subject: Re: Front bearing
To: Multiple recipients of list {[email protected]}
If you have the bearings in your hand and you even slightly suspect any
problem with them, or you have absolutely no idea how many miles they have on
them, replace them. Why? Because they are dirt cheap! Go to any autoparts
store and tell them you are working on your '69 (or '70) Ford Mustang (with a
302 or larger motor) with front disc brakes. Tell them you want two sets of
inner and outer front wheel bearings. Give them a $20 bill. With the change
you recieve, do not stop, go directly to McDonalds and have a big mac value
meal. Go home happy and full and install your new bearings.
Date: Fri, 20 Feb 1998 12:36:29 +0000
From: Mike Drew {[email protected]}
Subject: Re: Chamber Adjustment Bar
To: Multiple recipients of list {[email protected]}
}The rear camber on my car cannot be adjusted because all the shims are
already taken out of the lower arms and it did not give me enough adjustment.
Do the adjustable brackets in the engine bay solve this problem by pushing out
on hte upper a arm? Do they work or is it just show?
}}}I think the experts have weighed in against this notion. If you find
yourself in this situation, probably the best solution is a set of adjustable
upper control arms, which are available from most of the vendors. An added
bonus in these suckers is that they incorporate a heim joint which replaces
the super-expensive factory ball joint. Generally, I'd say that if your
factory ball joints are shot, instead of spending $500 replacing them (or
more), I'd look into getting entirely new control arms with the adjustment
feature, which will kill two birds with one stone.
Alternately, Wilkinson sells polished aluminum lower control arms which are
1/4 inch or so shorter than stock; this has the effect of bringing the bottom
of the wheel in, as opposed to pushing the top out. I've got a pair on my
car; they look beautiful, cost about as much as the factory arms (he charged
me $450 each I believe), and are undoubtedly much stronger; the only thing
against them is that they're super-heavy. Probably 4 times as heavy as the
stock arms, as a wild guess.
I wound up screwing myself by installing BOTH the Wilkinson lower arms and PPC
adjustable uppers; since my car's chassis was totally returned to factory spec
during its restoration, now I'm in a curious situation where I've got too MUCH
camber; I've got a billion shims under my control arms. Ultimately I'll
probably replace my adjustable uppers with my left-over stock ones. I hope my
stock ball joints are in decent shape...:{(
Date: Tue, 07 Apr 1998 14:38:44 +0000
From: "Franck, Donald J" {[email protected]}
Subject: RE: Ball joints and seals...
To: Multiple recipients of list {[email protected]}
} } I found that the previous owner had put electrical tape around the
} } exposed part of the ball joints on the rear A-arms. There is no "boot".
} } It looked like it had been there a long while.
} I'd check into the condition of the ball joints if I were you. I'm in
} the process of putting new bearings in the rear and found out the ball
} joints are $250 each! However, you can replace the seals/boots if the
} joint is alright.
Wow 250 each for ball joints. The adjustable a-arms I got from Pantera East
were 495 and I will not have to worry about ball joints again because the
heim joint replaces them.
Date: Tue, 05 May 1998 15:45:56 +0000
From: Cristiano Rossi {[email protected]}
Subject: Sv: Spring time (and measurement)!
To: Multiple recipients of list {[email protected]}
I have just changed my shocks and springs on my 1972 GTS. They worked fine,
I only changed them because they were 26 years old. I still have the
original shocks/springs in my garage, and I have measured the distance
between the centres of the two mounting holes in each end of the
assemblies. Both the front and rear shocks are - from the centre of the top
mounting hole to the centre of the bottom mounting hole - exactly 40,5 cm.
I changed to the 12-way PI Motorsports shocks/springs. These have adjustable
spring heights and 12 different settings for the shock absorbers.
For the spring height see page 76 in the blue owners manual: In front the
distance from the ground to the centre of the hole in the body end of the
A-arm must be 185 +/- 10 mm. In the back, the distance must be 175 +/- 10
mm. It is a very good thing that the PI springs are adjustable, and it is
quite easy to set them to the correct height. The front springs I got are
450 "something" (NM? Pounds?) and the rear springs are 550 "something". I
don't know how much "something" the original springs have.
I was advised to adjust the shock absorbers to 3 in the front (0 is minimum
absorbing, 12 is maximum) and 5 in the back, and then go on making the
shocks harder until I was satisfied. With the 3/5-combination, my rock-hard
GTS had suddenly changed to be a soft-springed limousine. I went on to make
the shocks harder, and now the settings are 8/9, but the car is still
softer than it was, so I will probably give it another couple of steps.
I suspect the 450 and 550 springs to be softer than the standard springs,
so they may be part of the reason that the car is still softer than it was.
By the way, the new assemblies weigh only about half as much as the old
ones that were really very massive and heavy.
If you have further questions, please feel free to contact me.
Date: Thu, 14 May 1998 16:33:41 +0000
From: Mike Drew {[email protected]}
Subject: Re: Rack Bushing Noise?
To: Multiple recipients of list {[email protected]}
What does the rack bushing noise sound like? A noise just started
that sounds like it's coming from the passenger side footwell. It's
cyclic with wheel rpm and does not seem to be affected by braking.
It doesn't sound quite like a wheel bearing and after a high speed run,
the lug nuts were still cool to the touch.
What's the drill for checking the rack bushing?
}}}I actually have REAL first-hand experience with this problem.
My car had a totally thrashed steering rack bushing when I bought it.
The original bushings (on the passenger side) are nylon and wear with
time; they can also crack and break down entirely.
The initial symptom was that when driving at freeway speeds around
gentle right-hand curves, there was a noticible juddering in the
steering wheel that went away as soon as I returned to straight ahead.
Here's the deal: The main bar of the rack passes through this bushing
and connects to the tie rod, and is supposed to ONLY go straight in and
out, which in turn, turns the wheel left and right. But as the bushing
wears, play is introduced which allows the main bar, and thus the tie
rod to move in other, undesirable dimensions (either fore and aft or up
and down, can't remember right now.) This movement will ALSO cause the
wheel to turn left and right.
To check for this problem, park the car with the wheels pointed straight
ahead. Jack the passenger side of the car ONLY, just enough to get the
wheel off the ground. (It's easier to have a helper for this test.)
Have your helper grasp the wheel at the front and back (3 and 9 o'clock)
and attempt to turn the wheel in and out (simulating how the wheels
would move if the steering wheel was turned back and forth. You should
position yourself underneath the car and watch for tie rod movement.
The wheel should barely move, if at all, and the tie rod should ONLY
move in and out a tiny bit (again, less movement is better.) If you can
see the tie rod moving fore and aft or up and down or ANYTHING other
than in and out, then your bushing is toast.
GOod news is, the new ones are only about $22, last basically forever
(they're machined from solid bronze), and installation takes only about
an hour. You don't actually have to remove the old bushing, the new one
just slides over the shaft until it bottoms out against, uh, either a
machined ledge inside the rack housing, or the remains of the old
bushing, I forget which. I installed a new bushing on my car parked in
the street in front of Jack DeRyke's house. Only modification necessary
is to drill a hole in the rack to install a set-screw. Realize that
you'll have to re-align the car when done (since you're removing the tie
rod end to slide the bushing over the shaft.)
Personally, I wouldn't immediately suspect a bad steering rack based on
your description of a noise only. If your bushing was bad enough to
generate an audible noise, I'd think you'd feel it in the wheel too.
Also, it WOULD normally be affected by braking and/or turning. I'd be
more inclined to suspect bushings or ball joints, or maybe brakes? (I
had a rear brake caliper partially fall off the car (one bolt jettisoned
completely, the other backed out quite a bit) and it fell down onto the
disc, the disc acted like a buzzsaw and started cutting the caliper in
half! It moved back and forth however, so the noise wasn't constant.
Suggest you carefully look over the ENTIRE front suspension area, and
don't rule anything out! :})
Date: Thu, 14 May 1998 16:34:46 +0000
From: Mike Drew {[email protected]}
Subject: Re: Rack Bushing Noise?
To: Multiple recipients of list {[email protected]}
What does the rack bushing noise sound like? A noise just started that sounds
like it's coming from the passenger side footwell. It's cyclic with wheel rpm
and does not seem to be affected by braking. It doesn't sound quite like a
wheel bearing and after a high speed run, the lug nuts were still cool to the
touch.
What's the drill for checking the rack bushing?
}}}I actually have REAL first-hand experience with this.
When I bought my Pantera, my steering rack bushing was WASTED.
The symptom I had was this: When driving down the road at freeway speeds,
when rounding a gentle right had turn, a pronounced juddering could be felt
through the wheel accompanied by a...well...juddering noise.
Here's the deal. The steering rack has a central shaft, to which the tie rods
are attached with u-joints. This shaft passes through bushings at each end of
the rack tube, and over time, these (nylon) bushings can and will break down.
Under normal circumstances, when you turn the steering wheel, the shaft moves
left or right, which in turn draws the tie rods in that direction and turns
the wheels. But when the bushing wears, the shaft is free to move in
undesireable directions (either up and down or fore and aft, I can't
remember), and this causes movement of the tie rod which makes unwanted
steering inputs to the spindle. In my case, when the tire was gently loaded
in a certain way, it would rapidly flap in and out.
To test for this problem, jack the car on the right side ONLY. Have a
helper grasp the wheel at front and back (3 and 9 o'clock) and turn the
wheel in and out (as though the steering wheel was being turned.) There
should be virtually NO movement of the wheel (make sure the driver side
wheel is stationary.) You should watch the tie rod and ensure that if
there IS any play, that it is very slight, and travel only goes in and
out of the rack. If the tie rod moves in any other direction (up and
down, or fore and aft, or some combination), and the wheel moves too,
then your bushing is shot.
Fortunately the fix is VERY easy, and cheap. In fact I did it myself
back in 1989, out in the street in front of Jack DeRyke's house. Took
only a bit more than an hour and VERY little profanity required! :})
The replacement bushings are machined out of bronze, and I think cost only
about $22 from the vendors. To install, you must slide the tie rod boot out
of the way, then remove the tie rod u-joint from the steering rack shaft. The
old bushing doesn't have to be removed, the new one simply slides over the
shaft and either bottoms out on a ledge machined on the inside of the rack
tube, or bottoms out against the old bushing (I can't remember which.) A
small hole must be drilled in the side of the steering rack tube to fit a set
screw into the new bushing to hold it in place. Then re-attach the tie rod u-
joint, put the boot back on, and yer done!
(Of course, you'll have to get the car re-aligned at this point.)
Note: If you buy the bushing from Pantera Performance Center in Denver,
they give you a nice instruction sheet. I don't know if the other
vendors do or not. :{(
Personally, I don't think the symptoms you describe fit a steering rack
bushing. If your bushing was so bad that you were getting audible noise, then
I'd expect you to feel some serious movement through the steering wheel.
Also, in my case the juddering WAS affected by braking and/or steering inputs,
and was only felt under certain very specific circumstances.
If I were you, I would closely examine EVERYTHING going on with your
suspension. I had a rear brake caliper essentially fall off the car
(one bolt backed out entirely, the other most of the way), and the disc
started acting like a buzzsaw cutting the caliper in half! That noise
was much like you describe. Don't rule out bearings, bushings, a brake
line fouling something, could even be that your wiper motor cover is
falling off and resting against the tire!
Let us know what you find out!
Date: Tue, 19 May 1998 12:31:17 +0000
From: Mike Drew {[email protected]}
Subject: Re: Steering rack bushings + other questions
To: Multiple recipients of list {[email protected]}
I've discovered that my steering rack bushings are worn, so I'm going to
replace them as described in the mails over the last few days. It
sounds like a simple job, but I have also discovered some oil on the tie
rod which appears to be seeping out of the rubber boot which seals the
end of the rack. I'm hoping that fitting a new bushing will magically
fix the leak, or is there something else I should look at (and possibly
replace the lost oil)?
}}}Uh, I'm reaching back into the far recesses of my memory here, but I seem
to recall that the steering rack is heavily greased, and in fact the boot is
designed to retain said grease. So if your boot is shot, then the grease will
seep out. So a new boot would be the fix there. Good news is they're
available and not very expensive. If your boot is still in good shape, maybe
a little tweak on the clamps would do the trick.
}I occasionally get quite a bit of bump steer, so I'm hoping that my
flailing(!) r/h wheel is the cause, but I've seen anti-bump-steer kits for
sale. Are these just steering dampers, or some sort of geometry change?
}}}This topic was beaten to death here a few months ago. It's a kit to
change the geometry. Check the searchable archives for all the info.
FWIW, I'm with Jack DeRyke in thinking that the factory fix for bump steer
(shimming the rack DOWN) is better than the aftermarket fix (which moves the
tie rod ends UP on the spindles.) I think we can get a bunch of shims whipped
out Toot Sweet (I'll try to get Larry to CNC some out of his super mondo
plastic), and if you come to the tech session (sometime in July?) we can get
your car squared away in a half hour or so.
}Also, when I realign the wheels, what toe-in should I set (with 225/50/15
}}}I'll defer to the experts here. Also, I saw in the UK newsletter (not
handy right now, sadly) a listing of suggested factory alignment specs for the
standard Pantera, GTS and GT/4 and GT5 (Euro models all.) Different specs for
all three; I'd advise using GTS specs. UK guys, care to reproduce them here
for us?
Date: Tue, 19 May 1998 12:45:43 +0000
From: Ted M {[email protected]}
Subject: Re: Steering rack bushings + other questions
To: Multiple recipients of list {[email protected]}
I actually "invented" the bushing fix back in 1989, and if you have the POCA
Tech Bulletin package from POCA, there is my article of how to do the fix
(using standard available Oilite bushing that have to be turned down on a
lathe). Many Pantera vendors are now supplying a machined bushing for this
fix. IT WILL NOT CURE A LEAKAGE PROBLEM. The rack uses 90 wt. lube that is
retained only by the boots on both ends of the rack.
I will try to republish the bushing article on my CHPIE page soon.
Date: Tue, 19 May 1998 18:52:07 +0000
From: JDeRyke {[email protected]}
Subject: Re: Re: NORWAY (mission completed)
To: Multiple recipients of list {[email protected]}
[[I got an emergency fax from someone named "Tommy" in Norway, asking for
frame dimensions to straighten a 81 GTS damaged Pantera.]]
Be aware that the last two pages of the white-page Tech Service Bulletins
(#47-11-04) has frame & suspension pickup dimensions for the '71-'74 cars.
They aren't very clear (won't scan) and use non-std reference points but will
be better than nothing at all, if "Tommy" has a frame machine available. J
Date: Mon, 25 May 1998 07:07:05 +0000
From: Forest Majors {[email protected]}
Subject: Re: Front Wheel Lock Nut
To: Multiple recipients of list {[email protected]}
Forest asked whats up with crimp lock nuts.
Thomas said "I replaced my crimp lock nuts and converted to cotter key locks a
few months ago. What do you want to know?
Actually two questions now... what manufacturer or automobile currently uses
a crimp lock nut that can be used on a Pantera - I need to replace mine.
The second question is what manufacturer or automobile has a cotter key lock
nut that can be used on the Pantera. Do you determine the cotter key holes
location in the spindle by using the same torque process on the lock nut.
i.e. torqueing the lock nut to 25 pounds, releasing the nut by one half a
turn then torquing the nut to 15 pounds? Assume that only a single hole
would be drilled in the spindle where the groove is and the distance from
the groove would be determined by the nuts "end location"
It really bothers me to have a throw away part like the crimp lock nut...
Date: Mon, 25 May 1998 10:05:56 +0000
From: [email protected] (Tomas Gunnarsson)
Subject: Re: Re: Front Wheel Lock Nut
To: Multiple recipients of list {[email protected]}
The Swedish DeTomaso Club has listed Fiat 132 crimp lock nuts as a
replacement. When ordering this winter only the left hand threaded nut was
available. The right hand threaded nut is out of stock and production by
Fiat, at least in Sweden. Probably not useful as a source in the States.
What I ended up buying is Lada (Soviet car brand) OEM parts that fit and were
available. These are most likely not availble in the States.
I had a total of six 3.5 mm wide notches milled in the nut collar (the part
that you otherwise would crimp). This gives me six positions per turn to lock
the nut. This is normal on other cars.
I then jacked up the car, replaced the nut and torqued the bearing with a
wrench to zero play (just using a few footpounds I guess). I then backed the
nut out until the notches I had made lined up with the axle groove. Using a
3.5 mm drill bit I just drilled through the axle with the nut guiding the
drill bit. Make sure you drill perpendicular to the axle! I then used a 3 mm
cotter pin to lock the nut.
If I'd been able to get castellated nuts with the correct thread it'd have
been the way to go, but as I had free milling I never took the time to find
any.
In an emergency the notches could be made using a hand file or whatever of
course.
The thread is 18x1.5 mm, right hand thread on the drivers side, left hand
thread on the passenger side. This is a standard metric fine thread, but the
left hand thread is probably tricky to find. As later Panteras are supposed
to have castellated nuts you might find that they fit and all that is needed
is to drill the cotter pin holes.
Worst case, buy original parts for an early car from one of the vendors,
modify them and pay the price of a cotter pin for each time you disassemble
in the future.
If I was to suggest a possible source for nuts apart from car parts stores
I'd suggest someone dealing with electrical motors and such. Pulleys are
often fastened with fine thread nuts.
Date: Mon, 25 May 1998 11:32:42 +0000
From: Bjorn Carlsson {[email protected]}
Subject: Re: Front Wheel Lock Nut
To: Multiple recipients of list {[email protected]}
}Actually two questions now... what manufacturer or automobile currently uses
}a crimp lock nut that can be used on a Pantera - I need to replace mine.
I picked up my nuts at a local Fiat shop. Russian Vaz (and maybe Lada) also
use the same nuts since they bought old tools and designs from Fiat.
Otherwise is a conversion simple. Just listen to Thomas.
Date: Mon, 25 May 1998 16:39:42 +0000
From: JDeRyke {[email protected]}
Subject: Re: Front Wheel Lock Nut
To: Multiple recipients of list {[email protected]}
{{Alas, I have discovered that I too have a crimped front wheel lock nut - not
one that uses a cotter key to secure it. I have searched the archives in
vain but I do recall some advise on this in the past. Now seeking same
advice again. Thanks... Forest Majors}}
I thnk ALL Panteras came with the one-shot racing-type front bearing retainer
nut. There have been aftermarket adaptions of every type imaginable, but
probably the simplest is to tighten up your nut properly, then carefully drill
a 3/32" hole straight down thru the nut flange AND the spindle and use a
cotter pin. A hole at this point is outboard of any stress so it doesn't
weaken the spindle. Readjusting later can require additional holes in the nut
flange, or shim washers to realign the holes. Just don't re-use the stock nuts
without caving in a lock section per spec's if you don't pin them! J DeRyke
Date: Wed, 27 May 1998 17:15:32 +0000
From: Andy Poling {[email protected]}
Subject: Re: Misc Stuff : correction
To: Multiple recipients of list {[email protected]}
} lock, the lock ring on the end of the tie rod is drawn inside the
} steering rack housing. If a second new (3 in total) bushing is
} installed in the rack, its outermost face is only about 1/2 inch from
} being flush with the end of the housing, which prevents the lock ring
} moving as far into the housing as it normally would.
Are you talking about the ring holding on the outer end of the rubber boot?
If so, I noticed that my replacement rack (from PPC Nist) has very long
(actually very stretchable) boots that could damn near reach all the way out
to the end of the tie rod.
Maybe you should look into getting longer replacement boots...
Date: Wed, 27 May 1998 15:06:50 +0000
From: [email protected]
Subject: Re: Re: Misc Stuff
To: Multiple recipients of list {[email protected]}
[[ Max, thanks for the tip, not sure exactly what you mean. Does this mean
that the bushing serves double duty as a 'rack stop' ? So bottom line do
you recommend to remove the orig bushing and replace with new, or install
new bushing 'on top' of old ? I need all the turning radius I can get :*)
Also is adjusting the pinion to rack preload recommended to reduce play or
is this a 'qualified technican job' I have an inch-pound torque wrench and
used it way back when on auto trans band adjustments ok. ]]
I'm not sure what he means either- the rack gear runs straight in & out and
the attached arms get nowhere near the bushing, so how steering could be
limited...? See the republished directions from Ted Mitchell circa 1978 (!) on
replacing a bushing {http://home1.gte.net/tmitch/chpie.html} As far as
'adjusting rack pre-load', welcome to the precision world of Italian cars. The
pinion gear is not adjustable at all, except for several precision shim
washers between the ends of the pinion gear. There is a spring-loaded shoe
beneath the rack gear at that point that keeps the proper tension on the
bottom of the rack gear (drivers side), so no support bushing is needed on
that side. IMHO, 98% of all Pantera steering rack troubles come from a
perforated boot allowing lube to leak out so the rack then runs dry, ruining
bearings, bushings & wearing everything out. J DeRyke
Date: Wed, 27 May 1998 17:23:39 +0000
From: Max Watson {[email protected]}
Subject: RE: Misc Stuff : correction
To: Multiple recipients of list {[email protected]}
No, the lock ring (see http://home1.gte.net/tmitch/Tech.htm ) which helps join
the tie rod to the steering rack rod is the part which is drawn into the
steering gear housing on full lh lock.
Date: Wed, 27 May 1998 15:40:14 +0000
From: Max Watson {[email protected]}
Subject: RE: Re: Misc Stuff
To: Multiple recipients of list {[email protected]}
Perhaps there's something strange about my rack or setup, but on full rh lock,
the lock ring on the end of the tie rod is drawn inside the steering rack
housing. If a second new (3 in total) bushing is installed in the rack, its
outermost face is only about 1/2 inch from being flush with the end of the
housing, which prevents the lock ring moving as far into the housing as it
normally would.
Date: Thu, 10 Sep 1998 12:58:11 +0000
From: [email protected]
Subject: Re: Source for Front Wheel Bearings.
To: Multiple recipients of list {[email protected]}
Front bearings are standard Ford, as found on virtually all Mustangs, pick-up
trucks, etc. etc.
Take your front end apart, pull the bearings on one side, go to Kragen to
match them. You should have new bearings in-hand for $20 in about 5 minutes!
Date: Thu, 10 Sep 1998 21:14:29 +0000
From: [email protected] (Steve Liebenow)
Subject: Wheel Bearings
To: Multiple recipients of list {[email protected]}
OUTER wheel bearings may be the same for a gazzill years as stated,
however,
INNER wheel bearing changed in 1970 to a larger size which then was used
for half a gazzillion years.... maybe to present.....
All the same, Kragen probably still has them both, whichever size you need.
Older bearing is going up in price though!
Date: Thu, 17 Sep 1998 14:47:29 +0000
From: [email protected]
Subject: Re: Steering Rack Lock Nut
To: Multiple recipients of list {[email protected]}
{{The question is: Is it typical for Pantera Steering Rack lock nuts to be
this tight? The nut threads correctly and quite easily until it is threaded
onto the shaft - but not to its original position. Once it is on the shaft
it becomes extraordinarily difficult to thread further back on the shaft.}}
Unfortunately, sir, it usually IS tight. I think people are paranoid about
having the steering rod loosen, along with not having the proper spanner so
the ring & nut can be torqued to specs. So they 'pipe-wrench' the thing tight
enough to distort the threads at that point on the rack, and forever after,
the ring & nut goes on with great difficulty. A fix would be to use the proper
re-threading tool to stroke the bent threads back in place (NOT a die since
that would remove metal, weakening the assembly). Sorry I can't be of more
help... J DeRyke
Date: Wed, 14 Oct 1998 15:04:26 +0000
From: [email protected]
Subject: Re: RE: Driving Tips
To: Multiple recipients of list {[email protected]}
{{I didn't like the amount of work required to modify the poly bushings to get
more than 4 degrees positive caster out of the stock upper arms. }}
Pat MIcal of Future Auto {http://www.patsauto.com} on the East Coast splits
the stock a-arms, then reshapes & rewelds them to allow up to 5 degrees. Don't
know if he further strengthens the stock arms, but these are what he runs on
his 1000-horse twin-turbo race Pantera. I'd guess these things radically
increase the heaviness of low-speed steering while doing good things @ high
speed. J deRyke
Date: Wed, 03 Jun 1998 16:27:31 +0000
From: [email protected]
Subject: Re: Leaking steering rack
To: Multiple recipients of list {[email protected]}
{{I have dry and tight boots on my rack but it leaks rather significantly
some-where around the rack/pinion connection (left side) where the steering
shaft connects - where/what is most likely the origin of the leak and is it
repairable? It seems to get too wet to really be able to determine where it
originates. Thanks to all}}
There is a seal up top where the pinion shaft goes into the rack, and a gasket
at the base. Other than a cut on the top of the boot, its gonna be one or the
other. Significant damage can occur thru wear if the lube level drops too
much, so I'd say, pull the rack out and find your problem area before you lose
the ball bearings or bushing. See the POCA newsletter article on bushing
replacement a couple of months ago as a pictorial guide. I think the seal can
be replaced without disassembling. J DeRyke
Date: Fri, 05 Jun 1998 16:21:21 +0000
From: Mike Drew {[email protected]}
Subject: Re: 7/8 front AND rear swaybar
To: Multiple recipients of list {[email protected]}
Seriously, in our extensive testing, we were SURPRISED to learn that
putting bigger sway bars on the front of the car HURT handling. The
optimal setup seems to be stock in front, 7/8" GTS bar in back. Also,
it's nice and CHEAP! :})
Then again, when discussing ultimate handling, there are different
theories depending on what kind of driving you'll be doing. Bob
Woodhouse autocrosses his Pantera with NO swaybar in the front and
claims it's the Hot Setup. PCNC never thought to test the cars in this
configuration.
While we're discussing this stuff, it's worth mentioning that I've
checked out a few cars with Hall Pantera's Spherebar swaybar mounts, and
I must say, although initially I was skeptical, now I think I'm a
believer. The owners have great things to say about how they have
improved things, and I don't think they're just trying to rationalize
the money they spent!
A couple of owners on the list have said, unfortunately, that they had
to shorten the brackets in the rear because as they come from Hall,
they're too tall, and the brackets will contact the spinning driveshafts
when the car is lightly loaded (i.e. airborne.) The argument that "That
will hardly every occur" isn't good enough for ME! All you need is one
good rise, you get the car light, then BANG the spinning driveshaft hits
the bracket, and suddenly things get ugly.
The guys who wrote in (and to be honest, I can't even remember who it
was anymore) said it was a fairly simple procedure to buzz off 1/4 of an
inch or so from the bottom of the bracket.
Date: Wed, 08 Jul 1998 13:53:02 +0000
From: [email protected]
Subject: Re: Suspension Noise
{[email protected]}
Rubber shock bushings isolate sound & road shock much better than urethane,
but also wear out faster. Usually, its the bottom bushing. When it collapses,
it drops the shock body down to contact the mounting bracket on the a-arm,
which may be where your noise is coming from. If you've got a shiny top/no
paint on the bracket & and little/no clearance to the shock body, thats it!
The rubber bushes from OEM shocks fit Konis & vice-versa. Could also be a
broken shock, though. J DeRyke
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