ZW 944

Hello all,

My dad just bought a 1995 968 Coupe 6-speed, Midnight blue metallic. its got a little over 100k miles, and drives wonderfully (just drove it back to ohio from florida this past week) the only thing is that its making a whirring sound from the rear of the car, much like what I've heard describing pinion gear failure. Unfortunately, I wasn't able to diagnose the problem before buying the car (myself being a 944 guy) but we got an excellent deal on the car anyhow. My question is that of all the things Ive been able to find about pinion gear failure (or rather incorrect shim spacing?) I'm not sure if its just hearsay, or factual.

Heres what I've heard:

a) pinion gear failure generally happened to cars at lower miles (less than50k)

b) Porsche/Getrag made changes to the assembly of the transmissions so that later cars don't have the problem.

so.... fact or fiction?

Also, what results from pinion gear failure if left alone for too long?

Thanks in advance.

Eric_Oz_S2

As I understand it, the sound of a failing pinion bearing is a jet like whine when off throttle (engine braking).
If you let it go to far you will need a new ring and pinion set (plus all new bearing obviously).
All years are susceptible.
See http://members.rennlist.com/martin/
Don't know what it sounds like but check wheel bearings and noise from torque tube bearings. TT bearings often fail (mine went at 80,000 miles).

swmic

My 95 had the pinion bearing done at 43 K.

RajDatta

Congrats on your purchase.
You want to make sure you identify it to be pinion bearing and not wheel bearing problem. They both can sound similar.
Raj

brianh

When I had my 968 the failure happened at 105K miles. I had the transaxle removed and shipped to Chris Cervelli in CO who fixed it & shipped it back. problem gone. I think it was around $2.5K total including having my local independent shop remove, ship & re-install the unit.

RajDatta

Chris is top notch. He is my transmission guy as well and has done quite a few of these either for me or a friend. It's not hard to remove the transaxle and ship it. You could easily save $$ by doing it yourself. All tools needed for the job are easily available at Sears.
I am DIY kinda guy, so I always push for people to do as much on their own as possible. Let me know if you need help on instructions and if you feel up to the task.
Raj

savvas944

just to be certain,did you change the g.box oil to see if the noise has gone away?
My car sounded the same,yurned out that the previous owner neglect to change the gear oil,and the
M22O zf discs churned it to watery black.
New good synthetic oil ,and new LSD discs ,brought it back to normal.Problem solved.

SpeedBump

Both fiction

ZW 944

Okay, thanks for all your help guys!!

new update, My dad said that he checked the transmission oil, and it looked clear and was up to the right level.

All of a sudden though, he tells me he's not so sure its coming from the rear of the car. Are there any other things that make similar noises from other locations? eg. Wheel bearings? The noise is definentally speed related.

Also, its good to know that theres somebody who has a good reputation for rebuilding these units in case that turns out to be the problem.

But, if we find out that it is indeed the pinion gear making the sound, should I tell my dad to stop driving it completely? So basically is it cause for immediate concern? or is it something that should be done the next time we get the chance? What happens if it fails?

I'm glad that removing the trans isn't too bad of a job. Ive never had to do it on either of my 944's, but I'd consider myself pretty mechanically competent, and my dad as well, he's just not quite as familiar with these cars.

phil0618

Hi,
I wasn't sure where my noise was coming from either, but yesterday we put the car up a jacks and ran it in 4th gear and my mechanic got close enough to the transaxle to confirm that was where the noise was coming from.