rear end vibration
Freshman User
Joined: Jul 2006
Posts: 44
Likes: 0
From: Coeur d' Alene, ID
If it started right after the lift was installed, I would check all of the bolts from the lift. It could be a loose leaf spring, U-Joint, etc. Also, did you replace the U-Joint? How many miles are on the truck? If your U-Joints are starting to go bad and you just put a lift on, that will definately make the vibration more pronounced.
Post Fiend
Joined: Jun 2004
Posts: 9,293
Likes: 10
From: Parker, CO
More than likely you have a two piece rear driveshaft, and the installers did not shim the carrier bearing. This causes a large degree of angle between the two driveshafts and causes a bind when you take off from a stop. This shudder is cured by dropping the carrier bearing down with shims or a bracket and returning the angle back to what it was prior to the lift. Look under your truck and find where the two rear driveshafts meet in the middle. There is a metal hoop with a rubber boot inside, that is the carrier bearing and that's what needs to be shimmed down.
The general rule of thumb is 1/4" of shim for every inch of lift. Meaning that a 6" lifted truck would probably need 1 1/2" of drop on the carrier bearing. Keep in mind though that not all lifts are the same, and some trucks require more shimming. On my truck in particular, I had to drop the carrier bearing a full 3 inches to cure the take off vibes.
The shim kits can be purchased from the manufacturer of your lift, or you can make your own with 1/4" thick plates and new longer bolts Just measure and drill the holes. Most likely you will install the shims, then have to add or remove a few to completely get rid of the vibrations. It's a trial and error game.
The other more expensive option is to replace the two piece driveshaft with a single unit. Most folks with 6" lifts don't require a one piece driveshaft though.
The general rule of thumb is 1/4" of shim for every inch of lift. Meaning that a 6" lifted truck would probably need 1 1/2" of drop on the carrier bearing. Keep in mind though that not all lifts are the same, and some trucks require more shimming. On my truck in particular, I had to drop the carrier bearing a full 3 inches to cure the take off vibes.
The shim kits can be purchased from the manufacturer of your lift, or you can make your own with 1/4" thick plates and new longer bolts Just measure and drill the holes. Most likely you will install the shims, then have to add or remove a few to completely get rid of the vibrations. It's a trial and error game.
The other more expensive option is to replace the two piece driveshaft with a single unit. Most folks with 6" lifts don't require a one piece driveshaft though.
