Annoying vibration that i cant find...

[2000strokers]

Im new on here so here we go. I have a 2000 7.3 PSD Crew Cab Short bed, it has a 3" lift kit that has a small leaf pack in the front and blocks in the back. Im not sure if it started after i put the lift on but theres a vibration 30mph up, it seems to kind of go away when i accelerate but comes right back at cruising speeds.

Really annoyed by it, looking for help please!

[HighOn22's]

Check bearing carrier angle. When you lift the rear you will need to shim your bearing carrier. This is done by inserting shims where the carrier mounts to the truck. It drops the bearing cariier down decreasing the drive shaft angle. If you look at several post down you will see others having these same issues.

[2000strokers]

Okay all have to add some shims when i get a chance. For a 3" lift how much shim do you think would be needed?

[HighOn22's]

That I am uncertain. I was told that the figure to go by is one shim for every one inch of lift. Have a couple of shims on hand. Add one at a time and see what happens.