Grinding while decellerating in 4wd.

Hey everyone,

I recently was driving in the snow and went to put my truck in 4wd and I got a very noticeable grinding noise from the front end area. No clue what it was, but I was thinking either Cv axles, my front diff, front driveshaft, or transfer case. The noise happens only when in 4wd and decellerating using either the engine or brakes. I have also confirmed that all 4 wheels do spin correctly as well. Does not go away when clutch is pressed in, and happens is all gears. Sorry if theres a forum already detailing this, but I couldnt find one. I appreciate if anyone has had this problem before and has any advice. All is welcome. Cheers!

 

I would get it up in the air, stick it in 4wd and listen to where the noise is.

 

The front driveshaft doesn't rotate on 2WD, so that's a good starting point for visual/tactile inspection. Spin the driveshaft by hand in 2WD and make sure it spins smoothly. Maybe your pinion bearing is shot. When was the last time you greased the U-joints?

 

Did you do any gear work lately?

 

I appreciate the replies. I guess I just got antsy with the problem and what it could be, but I looked under the truck and found that the front driveshaft was rubbing against the heat shield which was probably bent up for some reason. Everything is smooth and quiet now lol. Thanks!