does it make that same sound when the 4wd is working? That sound could be the transfer case engaged, but like i said the front hubs arnt locking in.

Try this, put the truck into 4 low, if you are locking in 4 low, but still not really full 4wd, then id say its in the front hubs, if you dont get locking into 4 low, (its not slow a crap) then you might have worse problems

 

No the noise was never there before.. I will try that in the am. Thanks for the idea's.. I will let you know what I find out tomorrow..

 

nothing in 4 low either.. I did try putting the transfer case in neutral and that did work.. Don't know I'm baffeled.. I have a friend at a garage, he is going to try to look at it today.. I will update..

 

Call me crazy but I'd think you got water into something you shouldn't have. How deep was the water or should I say how high up did it come on the truck?

I'd definitly check the fluids in your t-case, tranny and diffs for water.

 

I go through high water crossings (above the bumper) about 20-30 times a year, small flash floods are common here, and I've never had any issues. Your front diffs breather is up near the battery so you dont need to worry bout water in the front diff. You can relocate the rear diff breather.
I've never had issues with the 4x4 not engaging.

 

the water was up to my nerf bars and I have stock 17in rims..The noise sounds like it's coming from under the hood but I can't pin point it...

 

yeah just up to nerfs isnt gonna do any damage...

 

well something did.. maybe from the water splashing up under the truck it was about 100 ft. of road.. All I know is there is a loud whinning noise under the hood and the 4x4 won't engage...maybe I was going to fast and something got knocked loose or off under there.. I looked but don't know what to look for either.. these trucks don't have the vacume canister over the axel like the older ones..

 

no ramit is definately right. sounds like it was a cowinky dink that the high water crossing is where it actually failed. something else was about to happen regardless. Water only up to ur nerf bars isn't bad at all. and if it splashed the tcase look at it this way. what happens when it rains? t case gets water on it. sounds like something else bad has happened.

 

what happened? did you friend at the garage check it out?

When you were in 4low was it going very slow, were you in low, or was it driving like normal 2wd?