Strange noise from right rear of car

[hdrockerroller]

Ok everything on this 911 is either new or rebuilt. Rebuilt tranny, new axels, new wheel bearings new brakes, new bushings etc.. new in 2011, working great for a couple of years. Its an 83 911SC.

All of a sudden it started making a thunk thunk thunk noise from the right rear. It almost sounds like a tire problem but I tried the spare and it makes the same noise. Noise is really noticeable at about 30 mph in third gear. If I speed up the noise either goes away or gets drowned out by the exhaust.

I can see nothing visibly wrong with anything in the suspension, drive train, wheels or anything and I can't figure out exactly where the noise is coming from. Anyone have any thoughts of things to check? similar experienct? thoughs, ideas?

[K Sykes]

Have you checked the CV joint bolts? New axles sometimes loosen up.

[Scooter]

CV's +1.

You might also check your shocks.

[lucasdw63]

Agree. I am dealing with this problem as we speak. Just dropped my right rear axle to change the wheel side CV.

[fanaudical]

Weird thing that happened to me: The parking brake cable end would get hit by the bolts on the CV joint as it went round. I couldn't find it at first because having the parking brake set tensioned the cable enough to keep it out of the way.

[hdrockerroller]

Thanks for the replies. I checked the axel bolts and all are tight. Shock looks fine too. Also no sign of rubbing of the bolts on the brake cable. I do notice what seems like more noise coming from the wheel side CV joint on the right side of the car then on the left side of the car when I rotate the wheel back and forth. Maybe the CV joint is broken? Shame I can't just peek under the rubber boot and take a look.

[NoYouRelax]

I am hearing a similar knocking sound in my '83 SC. Will have to get under the car soon for a few projects and see what's going on. I will let you know if I find a smoking gun.

[TRE Cup]

Possibly cracked stub axle hub. Jack up the car and wiggle each rear wheel. Listen carefully for a clicking noise.

[hdrockerroller]

I spent this morning swapping out the axle with a brand new one. Old one appeared fine, noise still exists. I checked the shock while I was under there and there didn't seem to be anything wrong with it. I'm getting really stumped.
Paul

[tonythetarga]

just a thought. Check to make sure your pins retaining the brake pads are all the way in and/or the retainer spring clip is in place. The pads could be clicking if not held firmly in place. Could also be shoe for e-brake.

[fanaudical]

Wheel bearing?

[hdrockerroller]

Pulled the wheel, caliper and hub and inspected brake pads, and e-brake shoes, no problems or issues there. Everything looks fine. The wheel bearing is only 2 years old so unless it was defective it should still be good, doesn't really sound like bad bearing. And the noise only happens when its under power, accelerating or decelerating, not while coasting with the clutch in. thunka, thunka, thunka &(&(&

[hdrockerroller]

Checked all the motor mounts too, all are sound and securely fastened.

[tonythetarga]

Only other thing I can think of is the bushings in the banana, particularly the front bushing. It could have just enough play under load to make a noise.

[hdrockerroller]

All bushings are only 2 years old. For the sping plates it has polybronze bushings.

[ChrisBennet]

When you did your bushings, did you change the rear inner ones to monoballs by any chance? I had some and they wore out in a just a couple of years and made a knocking/clunking sound.

[hdrockerroller]

I used OEM factory replacement bushings from pelican for all bushings except the spring plate bushings where I used the polybronze bushings.

[simsalabim]

what about checking some weld joints?

sway bar bracket to body connection?

[nvr2mny]

I had a similar issue in my 930. Turned out to be the trailing link arm was broken, had to source one from the factory. Expensive, but fixed. Good luck.

[kbruz]

I would check the shock again. Specifically the shock tower bushings. Mine is bad on an 86 and everytime I go over a bump (which is California is now every road). I get a thump/bang from the rear end. The shock tower bushing is completely cracked and the shock tower bolt is banging around.