Vibration Underneath Truck

Yeoljb · December 21, 2007

I have a 99 silverado and I am experiencing a vibration under the truck when I accerate. The vibration starts under the cab and moves to the back of the truck as I accelerate. The vibration gets worse when I haul a load or tow a trailer. Does anyone have any ideas? Is it the drive shaft or something? Thank you for your help.

gsl2007 · December 22, 2007

I would block the wheels, set the parking brake and with the engine off put the truck in neutral. Try to turn the drive shaft and look at the u joints for play. If it's 4 wheel drive check the center support bearing especially the rubber mount around the bearing as well.

Genuinefine409 · December 23, 2007

Sounds like u-joints or the carrier bearing, usually a carrier bearing you don't feel from the start though, only as you get moving faster but anything is possible. mine was noticable from 40mph+.

gmtech4 · December 24, 2007

I have a 99 silverado and I am experiencing a vibration under the truck when I accerate. The vibration starts under the cab and moves to the back of the truck as I accelerate. The vibration gets worse when I haul a load or tow a trailer. Does anyone have any ideas? Is it the drive shaft or something? Thank you for your help.

hi,definite u-joint seized ,remove the rear shaft,you WILL find a seized u-joint or a loose sloppy one,,if the truck is 4wd you WILL break the t case adaptor from the vibration if left to continue,I am a gm tech and see it all the time,on a deisel with an allison the low/reverse housing is the adaptor,$2000.00 later ,hes on his way ,fix it now.

Yeoljb · December 24, 2007

Thank you all for your advice. The truck is a two wheel drive and I suspected all along the problem had to do with a bad u-joint and you guys have pretty much confirmed it for me. I'll check it out and let you guys know what I find out. Thanks again for your help.

1bad454ss · December 26, 2007

i have an 82 silverado that had similar problems. mine got so bad that i couldnt even drive it. it turned out to be the univrsal joints on the end of the drive shaft. i replaced bot ends and the problem went away.