My 99 4wd Suburban has a vibration or shake to it. I took it in to the dealer and they made me feel like they were just throughing parts at it, because they said after I spent all that money they didn't guarantee it would stop. So I concluded they didn't know what was wrong.

I lifted the front and tried to shake the wheels side to side, but they didn't move much at all.

It vibrates mainly at higher speeds which might indicate tires, but I've rotated them and it made no difference. I replaced the shocks and it made no difference. The vibration can turn into a shimmy at times. Where it feels like the front of the truck is shaking from side to side? It real bad when you go over pot holes or bumps in the road. It's like it shakes real bad and recovers to a vibration. The steering has had a lot of play in it also, but it has had it for some time with out the vibration.

It shimmied so bad one time I pulled over at checked the wheel to see if it was about to fall off. But no it was bolted on good.

Any ideas, or questions?

Thanks,
Jeremy

have you checked tie rods and sway bar bushings or stable lizer links and bushings? it sounds like a tire or shock but i see you put shocks on. you could also get a estament on the alignment and see what they find because it may be in your sterring box it's self....good luck..

The bushings look okay to me, but I don't know what's worn. They're there. They're not crumbly or cracked so I assume they're okay. The dealer said the tie rods looked worn, but wouldn't show me what they meant by "worn".

Thanks. That's what I was going to do next. There is a well known frame and alignment shop I was thinking about taking it to.

Look for play in the steering system, especially between the relay rod, Pitman and idler arms, and betwen the tie rods and the steering knuckles. Also look for the idler arm moving up & down as the steering wheel is turned...it shouldn't move in that direction. Any of a combo of these worn joints can result in loose steering feeling.

Also look for abnormal wear patterns on your tires...feathered tread blocks or cupping indicates worn or out of alignment steering or suspension components.

The dealer should be smarter than that...find a more reputable shop.