Rear end Vibration. Any Help!!!!!

[Phix_06]

I have a 2001 Z71 Ext cab 5.3L I notice between 45 to 49 MPH that the rear end of my vehicle has an even almost bounce. I have added a 3'' leveling kit to the front end and 285 75 16 BFG's. First noticed the bounce when the vehicle was stock but now is more prevelent than before. The dealership told me that they couldn't feel the vibration and leaned towards the tires being D rated, so no fix... After I picked up my truck my 2 year old child started singing because the bounce on the truck made his voice "sound funny" I have had the truck alligned and rotated the tires several time but the vibration stays in the rear of the truck, also had my rotors replaced and new brakes but no improvement. Any help on this matter would bew greatly appreciated. Thanks Dave

[dougod]

I have somewhat the same problem with my 2001 Silverado 2wd 4.8L.

I've tried 3 new sets of tires, but I still get an out-of-balance sensation in the rear end, especially at around 40 MPH. The problem is worse at some times than at others. I've tried rebalancing over and over again, but it does not seem to solve the problem.

Could it possibly be a warped or bent axle?

[Phix_06]

I have heard rumor that some of the trucks have a off balance drive shaft that would cause the vibration. Each dealer deny's that but like you said I have balanced rebalanced and rotated until i couldn't stand it any more. I wonder if GM has a site for questioning?? Let me know if you find anything else out. Dave

[barrow6]

Watch out!! Mine was doing that then the damn thing broke. Check the gears in the rearend quickly.

[Phix_06]

I don't think that it has to do with my gears. I don;t have any hard shifts or slips. The only thing that I notice is that it vibrates between 45-52 MPH. I recently deflated the tires to 30 psi because of the weather and no change. It feals exactly the same. "FRUSTRATING" I think that I am going to lighten the strain on torsion bars about 5 turns to see if it makes a difference. I'll let you know what happens. Dave

[Phix_06]

I reduced the tensoin on the bars 4 turns and it softened the ride a little but I still have the shakes. Any other ideas???

[Phix_06]

I think now that it might be tire related but I'm not convinced that it is not the drivetran

[70below]

I have a '99 silverado 4.3L auto 2wd that shimmys in the rear. I thought the tires were bad or needed balancing, tried both still shimmys. It can be felt occasionally at all speeds but really picks up and get noticable at about 65. If I pass 65 and hit the brakes it really shakes bad and will continue below 65 until I let up, when I reapply the brake its usually fine. Any suggestions? Bent wheel? Bent axle? Driveshaft out of balance? Other?

[Phix_06]

Originally Posted by do you need nuts?

maybe you should pull the vibrator out of your ass shithead

Grow UP and join the forum once your old enough to drive!!

[buttnekked]

The gears barrow6 is referring too are in the rearend.My best guess would be a bad pinion bearing or axle bearing. Check the driveshaft for play at the rear enor jack up the truck and see if either rear wheel has any wiggle in it.

[TXAGG05]

uh oh, mine started this shaking too at about 40mph, it goes away though at about 47mph and under acceleration or breaking. I was hoping that when I had time a good balance job on the tires would fix it. It only started since I rotated my tires.
Jeb

[TexasF355F1]

This may start making me feel a lot better knowing I'm not the only one.

If your driving down the freeway at around 65-75mph, does the rear end slide out and pull the truck over when you hit certain bumps on occasion??

[jeverett]

Has anyone suspected a farked up leaf spring? I haven't experienced what y'all are talking about, but it sounds like it could be a possibility??

[Phix_06]

THe only prob that I had with the leaf springs is the rubber spacer between the leafs. They wore out and were rubbing together so when I stopped and the truck rocked back it would rub and squeek