Rear Suspension Problems

[skizot722]

For some time now my 2002 LS V8 non-sport has been making a thunk'ing sound over certain bumps. When it does this, it is like a jarring feeling coming from the rear of the car (not super, super bad, but definitely not solid and smooth like it should be), like the suspension is bottoming out or something. It kind of sounds like the rear shocks are shot, but the car doesn't continue to bounce (however I have been told by someone on this forum that even when the shocks are bad on the LS, it won't bounce) and it only has approx. 27,000 miles on it. I can also feel the majority of the bumps in the road (I shouldn't be though, since it has the base shocks), and it definitely feels like I feel them from the rear of the car. It just feels to me like something in the rear-end suspension is not solid.

I got under there to look, not quite sure what I should be looking for, and saw that the control arm bushings are cracked and have grease coming out of them (both left and right sides, too). I will try to get some pictures up when I get home this evening. Does it sound like the control arm bushings are shot and causing the problem? Or does it sound like my shocks are shot, or is it both? Any help would be greatly appreciated.

 

[skizot722]

Here are some pictures. Any ideas guys?

 

[Quik LS]

yep - this has started to become a fairly common issue now.

Usually worn shocks cause a bouncy car - not the problem you are describing.

The issue usually is the anti-sway bar end links - they pop out under load, so they are hard to test since you can never really simulate the issue in the garage. But once 4000lbs is loaded onto the anti-sway bar and a bump hits - the endlink pops out.

There are many issues reported on the ball joints themselves - even a recall early on. I believe there are aftermarket options now - on e-bay.

 

[skizot722]

Quik, what do you suggest I do then? Take it into a shop? Also, with the anti-sway bar popping like you say, will this cause the ride abnormality I'm experiencing?

 

[jrizzle]

Yea its just a bushing, same thing happened to my mark, replaced the shocks as well, smooth as butter.

 

[Quik LS]

Well - depends on your skills and wallet. I would try to figure it out - get under the car and verify the issue. At least find a way to reproduce it. Once you are confortable that you know what it is - you can make the choice to pay someone to do it. I'm not usually a fan of taking a car in without knowing what is wrong - leads to paying a lot for troubleshooting...

 

[skizot722]

Well, I do know a bit about cars, just not a whole lot about newer suspensions like this one. I've already diagnosed that many of the bushing boots are cracked and leaking grease (some worse than others), but as far as troubleshooting more than that, I'm not sure what I need to be looking for.

So, if it is the anti-sway bar end links, you're saying that it would cause the bumpy "not smooth" ride, jarring and clunking I'm describing? The pictures I posted are not of the end links (they're of the control arms where they mount to the sub-frame [or crossmember]), and as far as I know, the end links use a un-greased bushing. I also thought the anti-sway bar was there to reduce body roll, and I don't feel like the car "leans" into turns. Nonetheless, how do I go about checking these components while I'm under there? And any other ideas as to what could be causing the problem?

 

[skizot722]

So, no ideas?

 

[n8bachelor]

I'm still trying to get over the fact that you have a 2002 LS with only 27,000 miles on it! I looked at a sweet black on black 06 with just over 28k on the clock yesterday. Sure would have liked to take her home with me.

 

[skizot722]

I'm still trying to get over the fact that you have a 2002 LS with only 27,000 miles on it! I looked at a sweet black on black 06 with just over 28k on the clock yesterday. Sure would have liked to take her home with me.

Yup. Which is why I think some people don't believe I would be having suspension problems with it. When I bought it back in Spring of '06 it only had 17,000 miles on it. So, I figure it probably did some sitting for those first 4-5 years (driven by an older couple), which may have had an effect on the rubber in the suspension (just a theory). I'm still not sure what the grease boots are all about on the control arm bushings. They usually don't use greased boots there, do they? (aside from the ball joint). The bushings look like they are pressed in, and I've heard people talking about having to replace the whole control arm when they go bad.

Any other ideas on what to check while I'm under the car? Should the stabilizer end links be tight, or should they have some play? I still think there may be a problem with the shocks since none of the bumps in the road are dampened in the rear, even though the car doesn't continue to bounce after hitting them.

 

[skizot722]

OK, so I was back under there again this evening. It may be the anti-sway bar bushings in the rear, but visually they looked alright. However, I don't think you can tell much just by looking at them, and they are rather difficult to see while you're under there on your back.

My question now is, should there be any movement when grabbing the anti-sway bar end links? I can grab them and move them around some, but I can't do the same with the end links in the front. I know the set-up is a little different in the front, and the anti-sway is much thicker around than the one in the rear, but there is absolutely no movement when grabbing the end links in the front.

Also, if the rear anti-sway bar bushings are bad, what effect would that have on the ride quality while moving straight down the road?

 

[jcharb]

Front or rear doesn't matter, there should be no movement when grabbing them, so they obviously need replacing and you might as well do the bushings while you're at it.

 

[TDUB]

I don't know what's wrong with it but my 01 has the exact same problem you've described and a clunking sound that comes from the drivers side rear.

 

[02LincLS]

Unhook the sway bar links and drive around. If it's quiet, its your links, or possibly (but not as likely) the sway bar mount bushings- I forget what the back looks like so make sure the bar isn't in the way of anything once you remove the end links.
My front does this and I know for sure its the passenger side end link. It's probably also time to do the mounts. My alignment guy gave me a part number for a crown vic that he said works (for the front) without having to remove the bar, but it's at home. I'll reply back with it later on.

 

[97stscaddy]

The best way to test end links is to disconnect them and move them by hand. The LS uses Ball joint style end links so if they feel loose then they're shot. You should be able to move them by hand, but not easily.

 

[skizot722]

The best way to test end links is to disconnect them and move them by hand. The LS uses Ball joint style end links so if they feel loose then they're shot. You should be able to move them by hand, but not easily.

Good to know. Mine only move a very small amount when giving them some umph, so I don't think that's my problem. What about the control arm bushings? How do you test them? If you look at the pictures above you can see the rubber boots on them are all cracked and leaking (on pretty much all of my control arm bushings).

 

[02LincLS]

they should be able to rotate, but there should be NO play or slop in them.