In 4wd, my left front end is making a bad binding noise. Jacked up the front end and the wheel is nice and tight; no free play. There is a lot of play in the axle itself as it comes out of the axle housing and inbetween the u-joint. How do I know which is needing replacement the u-joint or the bearing/hub? It makes sense that the bearing is hooped, but I thought the wheel always got loose then, too.

 

Jack it up after you engage 4wd, rotate the wheel and look at the ujoint. As far as the bearing goes, did you hold the wheel at 6 and 12 o'clock and push and pull?

 

Yeah when it was jacked up there was no play in the wheel whatsoever, in any direction. Just looked at it again and all the play is in the ujoint itself, so that is allowing the axle to have a lot of play in the housing. There is no play anywhere outwards of the u-joint. I guess this movement of the axle is tough on the seal?

 

know that the axle floats inside the tube, and doesn't touch the edges, nor have a seal at the outer end of the tube. its anchored at the diff and knuckle.

but, the u-joint should be tight, no play, none. no wiggle around the caps, which would mean the axle would rotate inside the tube, but not wiggle around any.

when you pull the axles, slide them out carefully past the seals, and slide them back in even more gently with lots of grease on the ends, otherwise it'll rip the seals.
how to here. http://www.pavementsucks.com/tech/hub.php

 

If you're replacing U joints, I HIGHLY recommend the spicer life U joints. They're stout pieces of work.

 

I totally agree. Cheepies from the parts store wont last long at all... not even a year with decent amount of abuse. Pay the extra coin and get good spicer joints, unless you enjoy changing them quite frequently.

Also, don't prolong replacing the worn joint too long. If it lets go while driving I can almost guarantee it will destroy the ears of at least one, if not both, of the axle shafts.