HI i have a 2004 ford f250 6.0 diesel i just put new warn locking hubs on it as well as the CV centering ball seat in the double cardan joint and all new u joints in the front drive shaft every time i put the truck in 4x4 i get a slight vibration in the front end area under acceleration and a squeeking rubbing sounds (sounds kinda like a bad u-joint) when braking or coasting at lower speeds, and this does not occur when in 4x4 and hubs unlocked, in 2wd with the hubs locked or in 2wd hubs unlocked. I took my truck to a local shop and they couldnt figure it out and they said the u-joint on the axles seemed to be in good condition. Can any one help me figure this out Thanks!

My under standing is when the truck is in 4x4 with the hubs unlocked everything spins but the wheels are not engaged to the axles which would mean the squeeking would be coming from the hubs but they are brand new. Makes no sense to me.

 

maybe they didn't chaulk the drive shafts before taking them apart and it's not phased right. see if all the u-joints are facing the same way.if one is just one spline out of phase you will have an unbalanced condition,hence vibration.