MCBigDog

Just got through replacing springs, shocks/struts, panhard bar/brace, lower control arms w/lowering brackets and upper control arm and bracket. Really like the level stance of the Sportline springs. The car handles very well although a little harsh over sharp bumps which brings me to my problem. I have a clunking in the rear when going over these sharp bumps. I've been back under the car and retorqued every bolt, everything is tight. It sounds like it's coming from the center so I'm suspecting the UCA but all bolts are tight and torqued to spec. Anyone have any suggestions? I did not replace the rubber bushing in the rear end housing. Could that be making all the racket? One other thing, the rear gear whine at cruising speed is almost unbearable. I expected a little more but nothing like this. Anyone else's this loud?

sbradle4

Did you make sure that the panhard bar is completely tightened to its shorter length? I had the same clunking after I installed my J&M adj. panhard, because i didn't tighten the end bolt on one side enough.

MCBigDog

Thanks for the suggestion. Double checked all rear suspension bolts and all are tight, including adjustable component lock nuts. Took everything out of the trunk including the spare and jack, looked under the rear seat, looked under the car, didn't find anything. Still getting the clunk/rattle especially at low speeds on rough pavement (my street). Very frustrating.

BrazenStang

Have you driven it without the spare tire, jack, and trunk mat? I had a clunk/rattle and I found out that it was just something loose in that area. With everything emptied out of the trunk I had no noise.

Norm Peterson

I bet if you disconnected every new polyurethane-bushed pivot you'd find that in several (possibly all) such locations the poly bushing material is longer than the inner sleeve that runs through it. What that means is that much of the torque you're applying isn't tightening through the sleeve, which is the way these joints need to be tightened in order to guarantee quiet operation. You're compressing the poly instead, and as soon as the suspension moves, the entire arm side of the connection slides until all the bolt OD to sleeve ID clearances get taken up (with a clunk).


Norm

Ford-a-tude

What Norm said. It's amazing how loud of a clunk a few thousandths can make. I have had my share of rear end clunks. The last one which I could not find for the longest time was actually the sway bar links. One bolt was loose where the link connects to the body.

Is your rear gear still stock? If your getting that much noise something else is going on.

UPRSharad

Did you cut the bump stops when you installed the Sportlines?

MCBigDog

I installed the bump stops Eibach supplied with Sportlines. I find it hard to believe that 130 lb-ft of torque won't compress poly to the sleeve but maybe so. I'll run around all the bolts once more when I have it up on a lift to install the exhaust. Squeaks and rattles drive me nuts.

The rear gear is stock 3.73. There was a little whine when stock. Now it'll drive you out of the car. I think it's going back to the dealer for this.

Norm Peterson

It won't compress it much because polyurethane is a pretty stiff material (perhaps 25 or more times as stiff as rubber) and it is almost completely surrounded by metal - IOW it has nowhere to go even if you could distort it enough, which is doubtful.

Never mind that any torque needed to compress the poly is essentially wasted effort as far as clamping the sleeve in place is concerned, which is what you want. Once the suspension moves (and the poly rotates in the joint slightly), you can only count on the clamp load through the sleeve itself.


Norm

MCBigDog

So, the solution is.........(if there is one)?