Clunks from rear

[vol96]

I dropped the motor/trans last winter in my 73 911 and since then I have this clunking sound coming from the rear of the car. I have re-tightened all the motor mounts, spring plate bolts, axle bolts, shock bolts and every thing else that I can find but the clunking persists.

It happens after the car has been sitting overnight as I back out of the garage and again when I first move forward. Once on the road there are no clunks and no ticking (like a bad cv might sound).

I cant think of anything in the rear suspension area that would cause such a sound except the cv joints. I did have them completely apart (ball bearings out, cages out etc) but was very careful when re-assembling......except I didnt try to return ball bearings to their original slot.

The car has been lowered and I'm wondering if perhaps this placed the cv's outside their normal range of angle.

I know that if you allow the cv's to swing in an extreme angle they can get stuck and a light tap with a hammer is required to free the joint.

Has anyone had such a clunking sound and was the cv joint(s) the problem?

Thanks,
Joe

[Neilk]

I had a clunk that quieted down after I replaced the spring plate and trailing arm bushings, IIRC. It's been a REALLY long time since I drove my car after redoing the entire rear suspension. Someone hit my car, and it's been undergoing "rustoration" for a really long time.

But in short, I would examing the bushings if possible, they were shot in my '73, and check the swaybar brackets.

Good luck.

[Roadrunner911]

Joe,
I had clunks coming from the rear of my 1982 911SC. A local mechanic said to try replacing rear stabilizer bushings. They looked good, but I replaced them with OEM ones from Pelican. That was it, no more clunks, quick and easy. Hope this helps.

[vol96]

Well I disconnected the rear sway bar and still have the clunk.

How can I tell if the spring plate bushings are shot? And what might cause them to make them to make the clunk. Everything seems to be rubber to metal.....no metal to metal to make the clunk......guess i'm missing something.

Thanks,
Joe

[Chuck Moreland]

The spring plate tube is supposed to be concentric in the hole of the spring plate cover. As the bushings wear and compress, the spring plate shaft becomes non-concentric.

If the spring plate bushes are sufficiently bad, the spring plate shaft will physically contact the spring plate cover causing metal-to-metal contact. This may not be evident when parked and may only happen when loaded up in a turn or over a bump.

Long story short, check for concentricity. If the spring plate is measurable out-of-center it is time for new bushings.