Truck (02 Sierra Z71) has a small vibration in normal driving. I can feel it through the wheel. Yesterday while doing a WOT run in autotrac it felt the the truck was going to fly apart. The truck shook so bad that soda splashed out of the can. What is the possible cause......wheel bearings, rotors, front diff.,transfer case. Where do i start to look. I have access to a lift. I just don't know where to start. Any help would be great.

 

I would start by rotating/balancig the tires. After that, take it to the dealership assuming you still have some warranty left. If not .. look on the driveshafts and check to see if the weights have flown off.

 

I had new tires put on 6k miles ago. No warranty left. Rotate and rebance as a starting point. Check the front driveshaft for loss of weights or should i just have both rebalanced

 

I have also seen vibration problems from the transfer case internals
How many miles ?
Every gear ?
What rpm or speed ?
Put it on a lift and run it in thru the gears
Mounts ?

 

38K miles, evergear, no specific speed, vibration is worse under throttle,
are you talking about motor mounts, trans mounts, transfercase mounts? The problem is getting worse.

 

sounds like maybe your driveshaft pinon angle?

 

that may be it............i had the torsion bars cranked and raised the front end about an inch. I did have a 4 wheel alignment right after but would that be enough of a change to affect the u-joints?

 

when I lowered my truck, it would vibrate a little (not as violent as yours) but I put the shims for the driveshaft pinon angle, and it fixed it.


I'm not sure how you would do that in a 4wd though.

Good luck

 

I'm willing to bet it's one of the driveshafts...

My SS is doing this now - Just like you said, it's worse under throttle. Mine's a hard shudder at times. Others it's just a mild hum or vibe. Some days it happens at 60mph ad up, others it only happens much higher.

It's not the wheels on my truck - I had some ice stuck in one of them. When I got on the highway, the truck was vibing bad, but different. It was a slower oscillation.

Adjusting the T-bar won't effect the front pinion angles any... It'll effect the CV's a bit, but I've never heard of them causing this much vibration. (they WILL vibrate when you crank the heck out of the T-bars on some GM's though - S10's for sure)

I'm about to call the service department and get my truck in there to get checked out. I'm really dreading this... I don't think they're going to go straight to the driveshafts on me. They'll probably balance the wheels and have me on my way.