2002 SLE - 100,000 miles. Recently purchased car - do not know history. I had 4 new tires installed and (supposedly balanced). Had a bad vibration coming from rear. No vibration in the steering wheel. Took back to Firestoned because there were NO WEIGHTS on the rear wheels. They re-balanced the rears and poof, weights appeared. I think they never balanced the rears. They claimed their machine was not calibrated ?? ... I am still getting an "out-of-balance" vibration coming from the rear of the car. Bad over 60MPH. I am going to have all 4 wheels re-balanced again somewhere besides Firestoned. If the vibration continues, could it be the rear struts ? How would I check them ? What else could I suspect ?

Have them spin balanced on the car. That way everything is balanced, not just the wheels.

I had a similar problem on a car a couple of years ago. Turned out that one tire was out of true and had a flat spot in it, which balancing cannot correct. A very easy check on this is to rotate your tires. If you feel the vibration in the front after moving the tires forward, you have a tire problem and not a suspension problem.

I noticed the same problem at speed, it was the bearings

Thanks everyone. I am trying to find a shop what will balance on the car - haven't found one in my town yet. I'm gonna keep trying that first, then switch the tires to see if it'* a bad tire, If it were a bearing, wouldn't you hear it if it was that bad ? I really think it is the balancing. It was terrible when the wheels had no weights on them at all, and just a bit better now that the have weights (and have been supposedly done right). I don't trust the Firestoned people because of that f**k up. I'll post a report after I try all these good ideas.

it could be your rear struts or at least one of them. if they are leaking than it could cause them to bounce very slightly when your going down the road. and you would feel this as a vibration.

to check them just jack up the rear of the car so the struts are fully extended and inspect for wetness under the boot.

struts are pretty cheap for our cars.

can be bought from rockauto.com

Bearings can be funny. I replaced my front bearing. It was causing an intermitent wheel vibration. Sometimes you can find a wheel bearing by sound, sometimes by "play", and sometimes it'* hard to tell.

There was some good advice from the others...
Jack-up one side and spin the back tire and look for roundness and side-to-side. Grab the top and bottom and check for bearing play. Grab the sides and shake, looking for bad toe link. Swap front to rear tires and drive. Repeat on the other side if no change.

Good Luck...

There have been a lot of reports of this same problem. I had this as well and no matter what I did, I couldn't find a solution. My friend (a 20+ year mechanic) had my car at his shop and they went through all the items listed in this thread so far. What finally fixed the problem for me was to have a road force balance. There are so many causes of vibration it can often take a lot of time and effort to finally determine the problem. For some reason, the 'H' body cars seems to be bad.

Have a look at this, no guarantees because it may be any of the other items listed above, but it did finally solve my problem.

Hunter GSP9700 Wheel Vibration Control System

Click on the top right tab for "Locate A GSP9700" to help find a machine near you. This is now the only type of balance that I get. I have noticed that when tires are brand new, a regular balance works. After a while, vibrations appear and this is all that has fixed it.

Thanks ddalder ! I found a GSP9700 at a Chevy dealer 5 miles from me. I'm gonna try that before I get too far into any of the other stuff. I agree a two dimensional balance is better. I'm gonna try to get it in tomorrow. I will report on the results.

That'* great. I'm looking forward to hearing if this solves your problem. Up here it costs $140.00 for a road force balance. It really doesn't take any longer than a regular balance but they obviously have an expensive machine to pay for. It was worth it for me because I spend a reasonable amount of time on the highway. The vibration was really starting to grate on my nerves.