I went on a drive with my wife last night and after our 2 hour drive, I heard a strange sound while going over a bump in the road. It wasn't a speed bump, just a imperfection in the road. The sound was something like a combination of a thud and a squeak (almost like a quieter bottoming out). It sounded like it may have come from the inside, so when I got home around 2am, I checked the shock tower bolts (all fine). I crawled under and checked all of the bolts I could get to (wasn't able to check the rear trailing arm-to-body bolt) and found my toe adjustment bolt just loose enough to move. I tightened it the best I could and now I'm going to have to get my alignment checked. Would the eccentric bolt being able to spin cause a noise during compression or would it just wear out my tires? I did check for play in the rear wheel while the car was on the ground, and everything seemed fine.

IMO, it can definitely make a noise, though I wouldn't expect it to be the one your describing, it would more so be a clank/clack metal on metal sound from the bolt.

If you are lowered, it may be wise for you to check your clearances in the rear between your tires & upper control arm/strut assembly. I know mine are close, I run 225's in the Rear, & it is damn close over some bumps, but still enough to clear. The noise you describe seems like a bushing/tire noise. From something loose, or worn.

Get out there & inspect when you get a chance.

Jeff.

Originally posted by 2ndGen-ElTalon
If you are lowered, it may be wise for you to check your clearances in the rear between your tires & upper control arm/strut assembly. I know mine are close, I run 225's in the Rear, & it is damn close over some bumps, but still enough to clear.

The wheel/tire assembly does not move independently from the UCA or strut assembly - I am not sure what you are describing here. If he was getting lateral or radial movement independent of the assembly then the obvious problem would be a wheel bearing. I run 245s (with an appropriate offset) and there is no contact.

I'm running 235/45/17s and I'm at stock height. Everything clears fine. Before tightening the toe adjustment bolt back up, I did hear a subtle squeak from the upper bushing in my knuckle assembly (polyurethane). I checked after and the squeak went away. Again, this is with the car on the ground. Being that I have almost all my tools at work, I'm limited to what I can check.

Well, I took my car to get checked and everything under my car is tight, but the sound is still there. I noticed that the passenger side is a little bit lower than the driver side (about a half inch), so I'm thinking my spring should be replaced (going on 280,000 miles). Am I correct in thinking that a worn spring can cause a thud in the back? If I go straight and hit a bump normally, there is no sound. However, if I go fast over a bump or hit a bump while turning left, you hear it.

Unlikely you have a spring issue - and you never, ever, should replace only one spring on an axle at a time.

That is a known quirk for 2Gs to sit lower on the passenger rear. Mine did before I had coilovers.

When I first got my car, I had to replace the spring on the driver's side rear (no choice). When I was replacing the shocks, I found that one side was using a Galant shock and spring. So I went to the local junk yard and picked up a spring.

I'm kind of curious about this myself. Mine has a clunk sound only when I'm turning right and going over bumps but not when going straight. :shrug

Here's a update: I dropped the car off at the shop before dropping my wife off for work so I could use her car. Being that it was in the 20s, the noise was even more pronounced. The guy behind the desk parked it in the back and he heard it. However, later on in the day when the mechanics had time to finally look at it, they couldn't make the rear make the noise. At least one of the guys heard exactly what I've been trying to explain, so they know I'm not full of crap...lol. I'm beginning to think a ball joint (upper contro arm?) might be going bad. I'll find out more today.

There is no upper control arm ball joint in the rear suspension.

Are you thinking the noise is in the front now? Why leads you to think of the upper control arm making noise more when it is cold?

I don't think it's related to the cold, but the fact that extreme cold seems to make sounds and/or noises more prominent. And sorry, I meant upper control arm bushings or lower control arm balljoint. My mind's all over the place and I've been thinking faster than I can type. LOL. With regards to the upper control arm bushing sleeves, are they installed dead center or would it not matter that much? The reason I'm asking is when I looked at both rear uppers, the driver's side bushings were centered, but the passenger's side are off center.