Topic: PLEASE HELP!!!!! LOUD RATTLE UNDER TRUCK TOWARD MID OR FRONT

[90runner976]

  hi everyone, i hope someone can help me with this rattle thats coming from under my truck..
its a 90 4runner v6 automatic with a 4" lift. its hella weird when drive in 2wd i get this loud rattle and it sounds like its coming from somewhere in the front or the transfer case. when im driving and i drop it into 4wd hi the rattling almost goes away, then i put it back in 2wd and its loud again. it sounds kinda like a bearing i think..  any help!!!  thanks !!!!!!!!!!!!

[WHITE_TRASH]

Check the u-joints in the front driveline.  Ill bet that at least one of them is toast.

[FIREBALL]

Are your hubs auto or manual? If manual make sure they are unlocked. If they are auto get someone to watch your front drive shaft while you slowly drive by in 2wd. If the drive shaft is turning when the t-case is in 2wd then you may have a hub that isn't disengaging. That would cause your front shaft to turn even while you were in 2wd, then when you put it into 4wd it puts a load on the shaft quieting it down. Still check your u joints.
This is just a possibility.
Good luck

[Fireimp141]

What they said 

[90runner976 [OP]]

i have auto hubs could that be the problem or maybe the transfer case or the front u-joints???
 

[Skinny_Pedal]

check the ujoints. those dam things can be trickey. my truck was rattling hardocre and shifted funny. it was the rear ujoint. my  . goodluck