Last month I purchased a 1994 Buick Park Avenue. So far I love the car, except I am having a problem with the rear of the car. If I drive it over any bump the rear end shakes/sways like I have a trunk full of Jello. Driving down the parkway and hitting a bump it feels as if I am losing control from the rear end. I have no idea what would cause this. This is my first FWD GM car (always had RWD full size cars). The only thing I know is that I have a small air leak somewhere on the right rear side, and I'm having rear struts replaced this week. Any ideas or suggestions would help. Thank you

check your rear sway bar, control arms, and hubs there may be something amiss there

X2

if it only does it when you hit a bump I wouldn't think it would be a wheel balance issue.

Rear struts being replaced is a good start. The issue you describe is vary bothersome to me however, it makes me suspect there is a major issue under there. When the struts are being replaced, have them look for any other irregularities. Also, an alignment will probably not be a bad idea also, as this also will flush out any major suspension defects.

I hate to throw money at something only to find out its more of a problem than it really is. But I'm gonna replace the struts and mounts with Monroe Sensa Trac'*. If that doesn't work then I'm gonna try replacing the sway bar links, bushings, and prolly the rear ball joints. If all that and an alignment doesn't work. Then I dunno what will help. Maybe be like that guy that drove to GM to demand they help him.

its only when i hit a bump or something like a man hole cover. it just doesnt feel very safe.

That is what has me worried. Typical 'really bad' rear struts usually cause a rear end that floats a little bit, and at worse, the rear end is really loosing traction over a series of bumps. Say if you were on a street with a slight incline to the side, and you went over a really rough patch, the rear end would slide down the road. What you are describing however is straight up bump steer. I suspect that when they to the struts, the issue is going to be obvious, as they should be able to see it.

What is bump steer? I havenever heard of it. I'm assuming that this is not a good thing to have occur? Is this something hard/expensive to repair?

bumpsteer is pretty much your vehicle steering in a different direction then you are as a result of hitting a bump. In your case your rear end is stearing itself as you encounter bumps.

How hard or expensive it is to fix depends on what is causing it, which can be any number of things. Any good mechanic doing your rear shocks should be able to take a look at things while they're back there and see if anything is hinky, which obiviously there is.

Bump steer is something that is an issue that people with lifted and modified trucks have to deal with. What will happen is that when a bump is hit by one or more wheels, the geometry of the suspension changes in a manner that causes the vehicle to try and change directions.