Hi,
I have a 2500 HD withe the 8.1. At 46-53 mph the truck vibrates. It does not matter if I am on the gas or off. Its not while I am braking. Any MPH below or above and the vibration goes away. Any thoughts? Thank-you vey much

oh I just had the tires balanced. It did it before I thought it was tires.

Thanks

Anybody have any thoughts on this? I have the same EXACT problem on my 01 Sierra 2500HD Crew Cab 4x4 8100. I've had tires replaced, still does it. I've put in a brand new GM 1-piece alum. driveshaft, still does it. I've had the tires rotated/balanced, still does it. It's maddening!! I'm down to a couple of options: bent wheel??? could bad shocks cause this?? I've done a search and it seems like quite a few people have this same problem...just between 43-49 mph on the gas or off the gas. Anybody have any luck fixing their vibration??

check driveline angles... both at rear of Tcase(tranny on 2wd) and nose of rear axle, need to be within 1-2 degrees of each other

Drive shaft?

I've seen it happen that way in other brands of truck.

My 05 crew cab long bed does the same thing even after changing the tires. I found a bulletin for chevy that has the tech's put 400 pounds in the bed and if the vibration goes away it's considered normal.

My 05 crew cab long bed does the same thing even after changing the tires. I found a bulletin for chevy that has the tech's put 400 pounds in the bed and if the vibration goes away it's considered normal. this is what they say it is called frame beaming. there is no fix

I just don't understand why it only shakes/vibrates/shudders at that one certain speed. About 45-50mph...it's driving me nuts. It's not driveshaft/u-joint related, i've put a brand new GM driveshaft in with new u-joints. It's not shocks, I just put Rancho 9000's on it today...still does it. I'm down to a bent wheel or rear axle related. :mad:

what year is this vehicle I will check tsb's for you

what year is this vehicle I will check tsb's for you

2001 GMC Sierra 2500HD 4x4 Crew Cab 8100

Any help would be greatly appreciated...like I said, I'm down to either bad wheel(s) or something in the rear axle/transmission. The whole truck shakes at 45-50mph then smoothes right out. Slowing down from 65-70 it will start shaking again at that speed, then smooth out under 45mph. It's crazy.