I have a 91 Camaro Z28 with Bilstein Heavy Duty Struts and rear shocks. It is standard height-hasn't been lowered. I had these shocks and struts installed over a month ago. A week ago I went over a dip going 25 mph it was unavoidable because it was dark. The next day the rear part of my car started feeling very soft, like the rear shocks were worn out-excessive rebound. I started hearing the creeking noise the day after. The creeking noise occurs when I go over speed bumps at 15-20 mph and over gradual hill-like bumps on the road at normal cruising speeds like 30-40 mph. I never heard the creeking noise when got the shocks installed. I looked underneath the car and from what I could tell is that the lower shock polyeurathane mounts are out of place- there not flush inside the shock. I haven't looked inside the rear trunk compartment of the car yet. Should I look there as well? I also want to find out if GM or any aftermarket company makes rear shock mounts for this car. Any comments related to this problem would be greatly appreciated. Thank you.

check the upper shock mounts i had that spongy feeling before and it was that i ripped the shock out of the upper mount i had to have it welded back together

Hey, Z28guy83, are you refering to the sheet metal where the shock poly insulator bushings mount on top of the shock? I'll check inside the car and tear out the black plastic covers. What caused them to break away? Was it tightened too tight on top?

There's no black plastic covers. All there is is the carpet, and some foam filler blocks to keep the carpet shaped.

The fact that the whole system is too weenie. The top of the shock just fastens to the sheet metal. If you put enough miles on one of these cars, the shocks WILL eventually punch the sheet metal out. Not a question of "if" or "might", rather a question of "when" and "will".

Compressing the rubber grommets won't injure the sheet metal and make it break. Sure, it's weenie, but it's not THAT weenie.

Hm them not having a recall on this is almost ... here's what mine did... *picture attached*

Edit: this just happened over the past 3 days sometime. I kept hearing a thunk and checked it out the next day. My shock completely ripped out the cone and the metal wasn't even between the bushings, it decentigrated completely. Fun stuff, there. Too bad I'm a poor college kid who hasn't been paid for $800 worth of time .. I could get shocks and weld it if I had the $$$$

Hey graywolfman, did you hear this thunk when you took off at 3/4 to full throttle and at each shift? What I am also hearing is a loud thud at 3/4 to full throttle off the line and the squeaking noise. Can an alignment shop do this kind of welding work? Wow, that doesn't sound good at all. Well I really appreciate all you responding to my post. I'll keep you posted on what happending. Thanks.

Holy crap! This kinda has me scared a little bit. My car is making a thunk sound on the rear drivers side, especially when I am turning a corner and coming to a stop and the rearend settles. I am planning on getting new shocks and springs because I believe they are worn out after 16 years. I hope I don't have any serious problems like this...

I went to my installer yesterday and determined my shocks are fine, it's just that they have broken in and also while driving over to the shock the softness wasn't noticeable. They ride well. The creek or sqeak sound came from the rear sway bar bushings that weren't lubed, so he lubed them and noise is gone, they are black poly rear swaybar bushings from Energy Suspension. Now, for the thunk sound. The noise is coming from underneath the console, now. I took it to a shop and had it road tested and determined it was the transmission mount. This sound happened after getting a trans fluid change. The tech from the other shop probably didn't tighten the transmission mount bolts tight enough so that is why I'm getting that thunk sound every time it shifts at 3/4 to full throttle, but, taking off gradually I don't hear it. I also looked inside the the car underneath the carpet and the shocks are still in tact with the sheet metal and the sheet metal hasn't ripped off yet. I hope it doesn't either. Thanks for your posts guys.

I have this exact same problem and I wish someone could just tell me in simple terms what is going on, that picture is that from the rear shock mount position? It is really annoying noise and i know its from the back after the car pivots in a turn or up and incline

Yes, it is from the rear shock mount position. The problem with the thunking, in my case, was the transsmission mount bolts were not tightened enough. I took my car to the shop where my suspension was installed. We performed the bounce test and determined the sqeak was from rear sway bar bushings rubbing up against the sway bar and lubed them and the noise was gone. I would suggest performing the bounce test and have assistant bounce the car while you try track the noise. Before doing this though, fold down your rear seats and pull the carpeting to one side to expose the rear shocks. Open your rear hatch, have the assistant get in the trunk and bounce the car up and down while you observe to see if the shocks are passing through the shock mounts. If they are, then the shock mounts are bad. If not shock mounts aren't bad, look underneath the car and inspect the muffler hangers to see if they aren't loose and check your rear sway bar links. Hope this helps. Pm me to let me know what happens or questions you my have regarding your suspension. I try my best to help as much as I can.

I had a car with a similar problem,and what I did was obtained a "Large Area Washer" that was just a little bigger than the area I had to work with.I cut it to fit the location,slipped one on the shock after all the normal "Rubber Bushing,and Retainer" and now it was going to be up against the bottom of the car.Going inside I did the same thing to the top side tightening everything. Then I drilled three 3/16 holes far enough away from the rubber "Bushing", but about a 1/4 inch from the edge of the washer evenly spaced from each other, and inserted 3ea "Steel" Pop Rivets. Presto .... hole is now only slightly larger than the Factory, and the Squeek and Rattle are gone.You could probably do the same with a piece of Sheet Metal, but the washers I found were pretty thick and the hole was about the same size as the raised area on the "Bushing".Welding the "Washers" would also be an option. I hope this helps.