heinrich

Why did the torque tube whine in my '88 auto?? Can you guess? Here is the '88 tube alongside a known good 86.5 tube. 88: "grind grind" ... 86.5: "whisper"

V2Rocket

Somebody installed the shaft wrong..

PorKen

Are those marked correctly? In the second pic, the left shaft has a circlip groove, and the right one is fatter.

heinrich

Same part number. Marked correctly my brother Ken.

PorKen

AFAIK, this is how it should look, unless someone's done some mix'n'match, broer.

James-man

Jealousy.

heinrich

Trust me on this. There is no question. See the bolts in the right tube? I put those there as I removed the upper bellhousing from the tube right there this am. That tube I personally pulled from my 86.5 I got with the kind help of Roger in Tx, the tube was sitting outside which makes it cleaner. They are labelled 100% as they came out of the cars

GregBBRD

Hmmm....You're not fooling with us are you?

Other than the shaft mystery, why did it whine?

gb

IcemanG17

H
The bearing has moved too far forward in the 88 tube....???

Black Sea RD

The longer 25 mm shaft with circlip groove is the older style "constant diameter" drive shaft which Porsche fazed out and replaced with the 28 mm thicker drive shaft to cope with the higher torque of the S4 models. When exactly Porsche stopped using the older style and when they started to use only the newer style is anyones guess. I doubt Porsche even knows.

However saying the above, it does seem the two drive shafts were placed in different 928s from when they first started. 86.5 is old enough for Porsche to have used the older driveshaft and 88 new enough to use the newer one.

Our cars are of the age and mileage that unless you bought the car new and know it's service history first hand, torque tube changes can have been done to the car without the current owners knowledge, even if he asked the prior owner. Either the prior owner has forgotten, can happen when you are not doing the work yourself and paying someone to do it, or the owner would rather not tell of this service for whatever reason.

As far as why the grinding noise problem, there is a noticable difference between the two driveshafts in their relation to their torque tube. The 88's drive shaft at the rear does not seem it is in correct position to have been properly held in the transmission input shaft and have the pinch bolt placed correctly in the grooved portion of the driveshaft. The rear bearing of the 88 torque tube also looks like it's resting too far back in the tube. The 86.5 looks to be in correct orientation to the torque tube. Can't tell anymore without being there.

Constantine
P.S. Nice to finally meet you at SITM.

heinrich

Likewise Constsantine I'm going to use the 86.5 tube (not the long thin one) in my 88 ... any disagreements?

V2Rocket

I think you should have one of the machinists on the board make you a perfect-fit torquetube out of pure titanium.

Godzilla deserves nothing less.

heinrich

lol you deserve a beer bro

Vilhuer

What you call as '88 has its center shaft too far forward. Check correct specs from WSM.

If you use thin earlier tube it would be good to use shims and circlip too.

heinrich

I think it pulled out as i pulled the trans/tube backwards out of the bellhousing .. I'm not calling it anything except the car it came out of