I am intending to buy an '88 to '92 S4 auto but I have read a lot about the problems with the load on the crank wrecking the thrust bearings and the engine block. Naturally I'm nervous about this but a} how common a problem is it? b} Is it mileage dependant? c} Is there a check I can do when looking at a car or are there any obvious signs?

TIA

Andy

 

Check out these links (thanks to Tony):

Crankshaft endplay & thrustbearing health

Pinch collar and drive shaft movement

 

Andy,

There's no sure way to test for Thurst Bearing Failure other than measuring for crank end play.

Typically, it happens between 30K and 60K. I haven't heard of any occassions where it has happened much beyond the 60K mile mark, except on those occassions where the torque tube has been removed and improperly reinstalled or replaced. Typical signs are hard starting when warm, having the motor stall at idle when warm, and overheating.

It's still a fairly rare condition, and shouldn't dissuade you from purchasing an S4 A/T. Just make sure that you release the front pinch bolt as part of you annual maintenance once you've become an owner.

Good luck on your hunt!

 

It happens, its rare, but dont let the spector of it keep you from buying one of these cars. Timing belts wreck more motors that TBF does.

If i were you, find the car you want, get the end play measured ..then buy it and drive it home. Every year go under and just release any tension that may have built up.

 

oops...double post

 

Checking the crankshaft end play is the way to check if the thrust bearing wear is excessive. It is important to stress that there is a way to ensure that thrust bearing wear is minimized.

I suggest that all 85 and newer 928 ATs have the flex plate tension checked every 30K miles or so. It is a simple task and only requires about 1 hr. labor.

I prepared a "white paper" with photos and outline of the steps. Anyone who'd like it, drop me a line.