KuHL 951

I've been trying to track down a strange light clunking sound in the L/R of the 83 (170K miles). Here's a brief history. My son bent two wheels (curb @25mph) about a year ago (F/R and L/R). Lately the camber on the LR wheel has gone positive about 1.5 deg. and is visually obvious with accelerated inner edge wear. This might be a result of the impact I don't know.

The noise is most noticeable at slower speeds both on and off throttle and isn't really bump oriented. I've checked all bushings, hatch closures/seals, heat shields, shocks, TA mount, axles, caliper/pads, muffler and hangers, spare tire, junk in the cubbies, and anything else that can make a noise. Everything is fine and tight except both wheels have just a bit more play than I consider normal when rocked top to bottom. The ride height is level so I don't think it's a torsion bar issue. I suspect a possibly cracked bearing case or just plain worn out bearings.

So my question is what sort of noise do failing rear wheel bearing make and how much play is normal rocking the tire like I described? I always found bad wheel bearings were more of a grinding sound and not a single clunk but maybe this is different. Sorry for the bad description but this one is stumping me. Replacing the bearings isn't an issue, no heating involved, but I don't want to just start throwing parts and Porsche dollars at a problem if they are still serviceable.

Thanks

KuHL 951

Anybody?

Dunasso

There should be no play. I know that this sounds remedial, but make sure that your lugs are tight. A loose wheel will make a clunking sound.

Also, bad axle bearings on the VW (early) style 944 suspension will make a gurgly sound. It will remain constant, under accelaration and deccelaration. If you can bring the car up to 55, try to notice if the noise becomes more exaggerated or goes away under left hand turns or right hand turns. This will tell you which axle is compromised. If the noise lessens under rt hand turns at speed, then the rt sd is compromised. If the noise lessens while turning left at speed then the lt hand side is compromised.

In any case, the car is old enough now that if you had to replace one side, you may as well go on and do both sides.

Duncan

KuHL 951

Thanks for the input but none of those symptoms seem to apply in this case...it's definately a slower straight line speed issue. The wheel lugs are at 95 ft. lb. and the noise isn't L/R dependent. There seems to be excess play in the bearings though. For the price of bearing/seal replacement at <$100 I'll probably give it a try but I think it's something unrelated. The failing rubber centered clutch was driven carefully for about 10K miles before I got around to replacing it; I have a bad feeling the sound could be damage to the trans from the start/stop shock on the R&P during use in 'Limp Home Mode' God these cars are FUN!

Dunasso

Did you check the axle nuts? That could also be a source of the inner tire wear.

Duncan

Mike C.

I recently replaced a bad RWB on my early 85 and it was making quite a racket - a grinding sound probably describes it best. Funny though, I'd been driving it for several months on a 1 hour each way highway commute to the new job and didn't notice anything strange. We then went on a weekend trip in our Subaru. Once back in the Porsche, the racket was incredible. Amazing what you get used to and just turn up the radio a little lounder.... Now if you had a cracked bearing race, etc, I'm not sure what that would sound like. Mine were just plain worn out (220K miles).

KuHL 951

Any nut torqued to 350 ft.lbs. is hard to check and seldom backs off; it's not like it can they come loose with a cotter pin through them. I've worked on cars for over 40 years and the obvious causes have all be checked. I think Mike might have it right, I got used to a car not making noise so new noises are suspect. The weird thing is the change in camber. Either the camber was knocked silly in the curbing and took 8 months to actually show up or something has collapsed internally on the suspension. Even a new alignment to correct the camber wouldn't explain the clunking, only the inner edge tire wear. Please, keep the ideas coming

tomrc

See if the exhaust is hitting the sway bar. I had that problem and it drove me nuts. Mine only did it during hard acceleration and cornering though, but worth a check. Wheel beerings should make a moaning? sound when going bad.

Dunasso

No argument here....only trying to help.

Keep pluggin' away at it and don't give up.

I'm sure you'll figure it out soon.

Best of luck,

Duncan

Granite 944

You describe it as a "clunking noise". ASAIK, and have experienced, with these cars, a rear wheel bearing thats bad, or one thats going bad, is going to make a sound of what I'd call more a bearing whine, or grinding noise. I would suspect your CV joints, as the most likely suspect of that type of noise. Especially if you can make it happen more at slow speed turns. I know ya said you "looked at" the axles, butt, it still may be the culprit. Turn them end for end, or side swap 'em side to side. You'll know for sure than. Sounds like your son threw the alignment off back there also, by curbing the car that hard. 4 point alignment is definately in order here also. There should be very, very, little play in the rear bearings, as checked up on blocks, top to bottom push/pull check, butt, some, isn't gonna kill ya either. Its just a matter of how much play. (stub shaft wear will be some of it).

I just did both rear bearing sets on my '83. I got rid of that rear bearing whine.........at last. No clunking was ever there.