in 4wd front end is making very not happy noises. its growlin' really loud, on the throttle, and a little bit off the throttle. can feel a vibration as well. completely stops when 4wd disengages.

first thought is pinion bearing. which is fixable. R&P i dont' really feel like replacing.

any ideas?

 

jack up the front of the truck, and start turning things. If it is a bad bearing, you should be able to feel it. Might wanna pull the cover as well, and see what kinds of rude nasty things fall out.....

 

hey speakin of, i just had my read end rebuilt, gears and all, driveshaft, transfer case pan,and tranny rebuilt, and when i am in 4wd and let off the gas, u can hear the front drive shaft or something "humming" down, i dont remember it doin that before, what u think? normal? it runs and drives fine while in 4wd. although i swar it used to drop right into 4wd, and now since they "fixed" it its like it takes a min to engage, like i gotta roll and get it to engage, but i got into some deep snow a while back and it took me like a whole min or rockin back and forth to get it to engage wtf? the wire harness goin into the transfer case maybe?

 

Front axle is vacuum actuated. Check the lines for rust/leaks... repair as needed. The CAD (central axle disconnect) is notorious for being problematic. Check the DIY section for the poor man's posi-lock.

 

sluggish engagement and disengagement of the 4wd light is related to the collar/fork not sliding back and forth promptly. the light is triggered by the fork or something? touching the switch contact on the end of the cad. mine has always been sluggish to move, using either the vacuum cad or the posilok. i think i've fixed it by doing 2 things -
1. replacing the small bushing and large bushing/bearing at the cad. these bushings are responsible for keeping the 2 shafts aligned.
2. filing the burrs off the splines of the inner shaft, so the collar can slide over it without interference.

 

thanks for the highjack x3 on your CAD

back to mine.

growl when on the gas. when coasting its not that bad almost non existant. vibes not really there. the great interwebs lead me to think its a pinion bearng. in 4x4 is only time it does it, so can't really spin stuff. it only happens in 4wd, so i've narrowed it down to either pinion bearing, ring, or Drive shaft. bleh.
after i'm done the lift i'll pull the cover and PRAY nasty things don't fall out

 

You can turn things by hand, and if there is a bad bearing, you WILL be able to feel it. Just don't have the 4x4 engaged. turning the driveshaft by hand will probably tell you more than you want to know.

 

when in 2wd -
front drive shaft, pinion, ring gear would not be turning, so no chance to make noise.
driver side axle and spider gears do turn. passenger inner does not turn. passenger side outer turns. both axles u-joints turn.
so since yours doesn't growl in 2wd, that pretty much rules those out.

growl sound is common for pinion bearing. if you turn the drive shaft back and forth by hand, you can probably feel it.

 

ok. thanks heyyou and dhvaughan.
will test tonight.......