well my 4wd makes a kind of loud humming noise in 4wd, when i hit the gas it gets louder when i let off it doesnt really but the noise is still there. so i was thinking it was the u joints or the pinion bearings or something internal, but today i unpluged the 4wd solinoids behind the battery so it wouldnt engage the front diff but i can still shift it to 4wd at the transfer case so the front drive shaft and everything inside the front diff and transfer case will spin. so i switched to 4wd to see if the noise was still there and there was no noise at all, and i know the front drive shaft and everything in the front diff was spinning. so im thinking that the front differential actuator isnt fully engaging the front differential causeing the noise. and it doesnt do it all the time but i have had it slip out of 4wd before like its not fully engaged at the front diff. once its in 4wd it stays in it. so i dont think that its a bent front diff shift fork. so im probly gonna replace the actuator and see what happens.

 

well its not my front differential actuator i took that black cover off today and engaged 4wd with the front wheels off the ground and the wheels engaged (aka they turned opposite directions). The actuator is workin perfectly i was suprised. But im glad i didnt spend 80 bucks for a new one when this ones not bad.