FreFro

Hello Fellow Rennlisters,

I have an issue with the driver's side rear axle (1981 Porsche 928 5 speed) that I would appreciate your insight on... I have replaced the driver's side wheel bearing, axle and drive shaft. When I tighten the axle nut, the drive shaft flange of the CV joint, makes contact with the back of the suspension knuckle and keeps it from rotating freely. Here's a picture:


Driver's side axle is contacting the suspension knuckleHere's a picture of the passenger side with the correct clearance:



Passenger's side with the correct spacing

I've checked the exploded parts diagram and didn't see a spacer, just the splines of the axle locking into the splines of the hub.... Any thoughts on what I'm missing?



Thanks,
Fred

Rob Edwards

Maybe the hub isn't inserted completely into the wheel bearing? Got a picture of the hub from the outboard side and how it's sitting?

dr bob

More critically, is the bearing sitting all the way into the recess in the hub carrier, with the large snap-ring seated properly in the groove in the carrier bore to secure the bearing in position? The stub axle position is determined by the position of the bearing, so if the stub axle ends up too far towards the outside, it means the bearing is also too far towards the outside.

Unfortunately, you'll need to go in with visual aids to confirm the snap-ring. There's no way to pull the drive hub out of the bearing without destroying the bearing. You can remove the axle nut and withdraw the stub axle and driveshaft, then check the clearance between the bearing and the shoulder in the inside of the bore. There should be none or very close to none measurable there. You are looking for a clearance there to indicate that the snap ring isn't seated in its groove.

;(

FreFro

Thanks for the feedback and suggestions, Rob and Dr. Bob. I inserted the bearing and large snap ring and verified proper seating of both. I also measured the clearance between the hub and knuckle on the driver's side and verified that it is the same as the passenger. Here are some pictures of the knuckle, bearing and hub:



Backside showing seating of the bearing in knuckle and hub in the bearing.

Spacing of the hub relative to the knuckle and emergency brake.

My current solution is to fabricate a spacer between the bearing a hub to establish the proper spacing. Any thoughts or other solutions?

Thanks,

Fred

JayPoorJay

I ordered my rear axle and carrier from that amazing west coast group on eBay... Although (and I'm sure they do there best) they had the descriptions as fitting, the two did not fit together and I had the same exact problem as you... What I learned (and am still trying to get sorted) is that there are differences between the stub end make up of the years to do with the 85 86 cars... Count the teeth on the ABS reluctor... It might have something to do with that. Mismatched axle and carrier.

dr bob

I obviously read your original description poorly.

Pull the two axles and swap them. If the problem moves to the passenger's side, it's the wrong axle.

JayPoorJay

Yup ^^^^ that

And if possible, a careful comparison between the stub ends of the old and new axle... The differences aren't super obvious but I found some in mine and sadly I cannot remember well enough to describe them. Let me go back and look at some of the photos and the thread about it.