Rear shock noise question

[Grover]

I've been hearing a "clunking" sound from the rear of the car when I go over moderate to large bumps for sometime, primarily the sound appears to be coming from the left side. To my untrained ear, it sounds like something is not tight. Today I swapped the two rear shocks to see if the sound moved to the right, and indeed it seems to have. So, I'm almost at the point where I think it is a blown shock. However, one thing I noticed especially on the noisier of the two shocks is that the threads where the nut mounts on the top side show that the nut is potentially bottoming out on the threads, and I wonder if it is giving a "false tight" reading but still allowing movement of the shock within the tower. In terms of upper bushings, there are just matching 1/4" thick (or so) bushings top and bottom as well as matching 1 1/2" diameter washers either side. Are there different thicknesses of bushing which perhaps wouldn't allow me to bottom out on the threads? Does this sound like a viable scenario or should I just replace the shocks and be done with it?

[hpsenicka]

If there is any evidence of oil leakage from either shock don't waste any time thinking about it and just replace them.. both of course!

Also, if you extend and compress the shock thorugh its full range of motion while unistalled from the car, and hear any noises, or feel any irregular damping.... see answer above... replace them!

[Guest Anonymous]

First of course determine if the shocks have life in them. If off the car,

run the pistons in and out. They should be same in feel. You can do

a bumper press if they are on the car. No bounce...the shocks should dampen this. Next, check for tightness at the upper end mounts as you noted. The rubber bushings should be slightly compressed. Make sure that the threads sticking out of the shock piston shafts are about the same number. The shock bushing might be rotted out on the down side. They can be replaced and aren't that expensive. Might be worth it if there is any doubt

about them. Put soap on them and they'll slide in with a couple of pushes. Wiggle the rear axle stubs with or without the road wheels on. Make sure that the rear bearings are not worn out. They might clunk if starting to fail. Torque the 22mm bolts that hold the subcarrier frame in place. These are the ones near the rear jack points, left and right. They are a rubber mount so not too tight (I know they have metal in them.)...but they are a target for looseness. And they clunk if loose. Muffler hangers should be intact...make sure that the clunk isn't an exhaust pipe or muffler...hitting the undercarriage. Make sure that the bushings that hinge the trailing arms are intact...and the bolts that go through them should be tight as well. That should be enought to get you started. As you might guess...I've spent time chasing these gremlins as well. Good Luck.

[Grover]

Thanks for the replys so far. The shocks don't appear to be leaking any oil and moving them through their compression range I didn't notice any sounds or strange bumps. One thing you mentioned is that the bushings should go in with just a little soap. Mine however, are virtually flat with just a very small bump on them that inserts into the hole in the tower. The bump on the bushing is a significantly smaller diameter than the hole in the tower, so in other words there is the possibility that it is moving within that hole, if that makes sense (is this abnormall??). I've checked the tightness on all the bolts holding the subframe in place as well as the integrity of all the urethane bushings, and they all APPEAR to be in good shape. I'll have to check the sub-frame mount bolts tomorrow. Keep the ideas coming, at this point I'm ready to try anything.

[Guest Anonymous]

Grover: A quick reply. The rear shocks should have a pretty meaty

bushing in the body tower mounting hole at the top. The correct rubber

bushing is about an inch and a quarter tall, with a groove about mid height for the body metal to lock into. The bottom of the bushins is tapered to wedge into the hold When in place, there is rubber above and below the mounting place. There was, if I remember correctly, a metal insert that helped keep the bushing from squishing down under tightening torque. Put a 5mm hex in the center of the shaft, or a square wrench on the tip of the piston rod and tighten with 15mm openend wrench (I think it was a 15mm.) It sounds as if the previous intallation of rear shocks used a split bushing with a washer below, then underneath rubber, then body panel, then top rubber then washer on top. If not tigtened properly these can wobble in the hole causing noise or bumping...I understand that these tower bushings are still obtainable but in fact I put mine in four or five years ago so I'm not sure. Good Luck.