GT posi failure


ARBOC72

GT Owner
Jan 3, 2009
7
Does anybody know where I can get a transaxle diagram and parts? I think my posi has gone away. I had no idea it was bad until it did a 180 under moderate acceleration. May be why there are so many wrecked GTs for sale.
 

tmcphail

GT Owner/Vendor
Mark IV Lifetime
Apr 24, 2006
4,103
St Augustine, Florida
Does anybody know where I can get a transaxle diagram and parts? I think my posi has gone away. I had no idea it was bad until it did a 180 under moderate acceleration. May be why there are so many wrecked GTs for sale.

email me torrie@fastpartsnetwork.com
 

MAD IN NC

Proud Owner/ BOD blah bla
Mark IV Lifetime
Feb 14, 2006
4,219
North Carolina
ARBOC72, before you blame or look at the rear end - what were the conditions when you spun..

Temperature?
Road temp?
Time of day?

Could be the Goodyears! When at ~55F the are like a wheel of steel and VERY unforgiving. They break loose in a millisecond! This has been discussed hundred of times on the forum.....



Where are you located at?
 

B O N Y

MODERATOR & FGT OWNER
Mark IV Lifetime
Sep 5, 2005
12,110
Fresno, Ca.
Are you a FGT owner, if so register your car in the registry, and advise.
I doubt the posi has anything to do with the wrecked GT's. The problem is with the 6" between the driver's ears.
 

thegtguy

*Supporting Vendor* GT Owner
Apr 20, 2006
552
MI
GT

Check your alignment. If a rear toe link is loose/bad/worn it throughs the whole car out. We had a car that was worked on someone else and the customer brought the car to us and complained about the car pulling hard to the left under hard accels.
It was a bad rear toe link.

Rich
 

mousecatcher

GT Owner
Jun 26, 2007
200
San Mateo, CA
doesn't the FGT have a torsen-type LSD? i didn't think they could go "bad".
 

ARBOC72

GT Owner
Jan 3, 2009
7
Something is wrong. With car jacked up and idling in first gear, I can stop either wheel by hand and the opposite wheel continues spinning.
 

B O N Y

MODERATOR & FGT OWNER
Mark IV Lifetime
Sep 5, 2005
12,110
Fresno, Ca.
please answer the questions already presented to you...
 

ARBOC72

GT Owner
Jan 3, 2009
7
As to weather conditions-40 degres F, Dry road, 10am
 

ARBOC72

GT Owner
Jan 3, 2009
7
As to my status. I own a white w/blue stripe 05. I thought I had registered it.I'm new here . I don't know how to put it next to my name.
 

B O N Y

MODERATOR & FGT OWNER
Mark IV Lifetime
Sep 5, 2005
12,110
Fresno, Ca.
I changed it, now you can see other areas of this forum.

we are an owner's forum, unlike most. Please answer the questions in post 3 and 5.
Nobody knows more about GT's than the poster in number 5 - RICH BROOKS the GT GUY.

We are trying to help you.

Oh yeah... welcome to our forum.
 

Fubar

Totally ****** Up
Mark II Lifetime
Le Mans 2010 Supporter
Aug 2, 2006
3,979
Dallas, TX
Probably to simple... but check your tire pressure.
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,704
Belleville, IL
I'll guess I'll be the devil's advocate - did you have the half-shaft bolts replaced according to the TSB under warranty? Do the axles feel loose?
 

Team Jeff

GT Owner
Sep 8, 2007
561
-40f is pretty damn cold to be running around in the GT! :wink

Seriously though, if the differential failed in the sense that it would no longer provide equal power to the rear tires on asymmetric traction surfaces, the result would be the opposite of what ARBOC72 described. Only one rear tire would lose traction and the other would keep the car traveling straight. The one wheel wonder :lol.

Torsen diff's behave like an open diff until torque is applied, then it will "ramp" up depending on power input. The word torsen is actually a combination of "torque" and "sensing"... fyi.

It could very well have been some oil or dust/dirt on the road. Or like Fubar suggested tire pressure.
 
Last edited:

GTNJ

GT Owner
Mark IV Lifetime
Sep 21, 2006
1,611
State of Confusion
Alright ................. I'll ask this question .

The FGT handles alot differently than most other exotics.
You got to get used to its peculiarity's.

So ................... how long have your GT?

Oh ............. and welcome to the forum ......it's one big family. :thumbsup
 

dbk

Admin
Staff member
Le Mans 2010 Supporter
Jul 30, 2005
15,247
Metro Detroit
40 degres F

I'm going to assume this is the answer until proven otherwise. Rock hard goodyears, acceleration and 40 degree temps often result in spins.

I have never heard of a GT spinning because of a screwy diff. I have heard of many spinning because of cold temps and driver error.

Let us know what you find out.
 

silver1331

GT Owner
Jan 31, 2008
414
Chicago, IL
Does anybody know where I can get a transaxle diagram and parts? I think my posi has gone away. I had no idea it was bad until it did a 180 under moderate acceleration. May be why there are so many wrecked GTs for sale.

It's the car - its a BEAST! As a novice GT owner i did a few 180s under moderate acceleration...pretty fun when you learn to control them. My car has Michelin PS2s, which are MUCH better than stock goodyears.
 

ARBOC72

GT Owner
Jan 3, 2009
7
Thanks for all the replys. To answer some of the questions. I live in Mechanicsville, VA. I've had the car about 2 1/2 years, put 4000 miles on it and tracked it a few times. I also own a couple of Vipers, Diablo VT, Cobra and various other cars. Rear suspension looks fine,tire pressure good,had half shaft bolts replaced.I'm no expert, but I've been a gearhead for about 45 years.Why is the transaxle such a mystery? Can't seem to find a diagram anywhere.I drive my cars all year as long as there is no salt and sunny out. That's what they're for.Does anybody know how to check the lsd other than what I've done? Thanks again.
 

dbk

Admin
Staff member
Le Mans 2010 Supporter
Jul 30, 2005
15,247
Metro Detroit
I think there is probably an exploded diagram of the trans in the SAE papers. I just got the book, but I haven't looked through it. If you look on the SAE website you can buy either the individual papers or the whole book.
 

Silverbullitt

GT Owner
Mar 3, 2006
1,757
Lago Vista, TX
I don't know if a transaxle needs a posi. The reason for a posi is that the right rear wheel is lifted due to torque against the rear axle. With a transaxle bolted directly to the motor the torque is offset and there should be no weight difference between the rear tires ever. Any pros here have a different answer?