I bought the truck like this and it has the 1st gear and sometimes 2nd vibration. I read a little about this in another thread and was wondering if my driveshaft was put in wrong at one time. My carrier bearing does have a piece of rubber starting to peel or tear, doesn't look like it would affect it though.
How do i tell if its out of phase? How should the u-joints be aligned?

I can't look at mine right now, but IIRC, the yoke at the t-case and the one that bolts on should be parallel. (Aligned) The long section is welded in parallel. The tow shafts are 1/4 turn to each other when assembled.
I'll try to remember to look when I leave work.

If it is jumping around because it is out of phase, it will tear up the rubber around the bearing in no time at all.

Mine is just starting to tear, but it could be from age too. The vibration could be a combonation of that and wheel hop on my wore out springs.

An out of phase shaft will vibrate badly with any speed at all.

When mine was out of phase, it buckled upon initial accelleration and felt like axle wrap. It smoothed out from 2nd gear on up.

quote:

Originally posted by Reserector:
When mine was out of phase, it buckled upon initial accelleration and felt like axle wrap. It smoothed out fron 2nd gear on up.

Thats what mine feels like its doing.