I have a very bad vibration in 4x4 whenever I got over 20 mpa and a bad cluck on the drivers side when i make sharp turns or pull in to driveways, etc.,. i took it to the dealer and got a call back a couple hours later saying the cannot fix my problem. But the told me it was a lose bolt on my fabtech lift that connects the differential to the frame. so I get the bolt out that was very lose, like they told me. So I tight in back up and throw some locker on it and I sill have the same problem. any one have any idea what it could be ?

 

What year truck?

It sounds like your front driveshaft wasn't keyed like the instructions state.

 

its an 04

 

Yup, key the front driveshaft correctly as per the instructions. It will fix your problem!

 

thanks!