I've got a vibration in my 97 Suburban K2500. You can barely start to feel it at about 55mph, gets very noticeable at 65, its worst at 75, then smooths out ALOT at 80+. Tires are a month old, and I've had them re-balanced 2 times. The rear driveshaft has brand new u joints and was just balanced. I don't think its the front driveshaft because removing it makes no difference. I have not yet checked motor mounts or the trans mount. I was thinking it could possibly be the shocks. The truck sat for a while before I bought it and the tires it had on it were flat spotted really badly, to the point that the truck was impossible to drive above 40mph due to the tires making it shake violently. My thought was that this violent shaking could have wiped out the shocks. The shocks do look old, but don't appear to be leaking or anything like that. The truck rides smooth (as smooth as a 3/4 ton anyway) up to 50mph. Opinions?
Thanks
Thanks