Oldsmobile/Buick Repair: 2000 GMC JImmy Shudder/vibration at 60 MPH, cv boots, ball joints


Question
Hi, Van, I've seen similar issues addressed here, was wondering if you might have any insight. This vibration is from the bottom/rear, not the steering column...starts around 60, then goes away around 70 mph. The tires were replaced, along with ball joints, CV boots, shocks, tie rod ends, idler arm...driver shafts and U-joints were checked and shown to be ok, as well as motor mounts, shock mounts, frame (not bent). Also had the rear stabliliser checked, and there was some parts replaced there as well. the only consistent answer I've gotten from the dealer and an outside shop is that the tires are bad. The road force ratings were 8, 16,18, and 24. The tire shop took the one with a rating of 8 off and replaced it with one that had a rating of 22. I was not happy with that at all, it sounds criminal to me. The President of the tire shop had me bring it to the main facility, they played around with tire pressure and adjsuting the raod force ratings, still no change. Are we missing soemthing? Or is it just the tires being bad?  

Answer
I assume they checked for a bent wheel?

I would put it up on jack stands or a hoist, and look under there as someone ran it at about 70.

Another thought is to see if a friend has wheels that will fit, and completely swap tires and wheels for a test ride.

Van