4x4 Grinding noise

[Matt Goodwin]

This being my first post I want to start by saying hey. This is my first yukon. I've wanted one of these for a long time and was lucky enough to be able to get my hands on a Denali that was in decent shape.

Let me get to the problem now...

The one thing that is baffling me is the 4 wheel drive. When I put the truck in 4 wheel it makes a grinding noise that is not present in 2 wheel. The noise only occurs when moving. I checked the t-case and it has plenty of fluid(probably needs to be changed, but is full at the moment). From what I've read on this site and others it would seem to be a t-case problem. Is that right? If anyone could give me advice on tests I can perform to determine if it's the t-case, hubs, axle, etc it would be a huge help.

One thingI thought of doing is putting the truck up on stands, disconnecting the front driveshaft from the t-case and seeing if it still makes the noise. Again, any help would be very much appreciated. Thanks!

 

[ccapehartusarmyINF.(ret)]

okay first question my apologys im not trying to be smart ass but ive read posts on here were this was the problem so
Are you putting it in 4wheel drive while on pavement? if so i hope yer not making sharp turns and if so go find a gravel road somewhere any kind of loose ground

 

[abishoff]

Also, what year is this? It was my understanding 2000+ Denalis are AWD

 

[ccapehartusarmyINF.(ret)]

is AWD an option on the denali cuz it sounds like hes got a 4wd xfer case

 

[abishoff]

is AWD an option on the denali cuz it sounds like hes got a 4wd xfer case

I was fairly certain that awd the only option. But I could be wrong. I know the escalade could be rwd or awd

 

[AppocAlexx]

Year and what step up you have would be a good thing to know as well. If you have a leveling kit that is too high with stock suspension your front shafts will be at bad angles and could possibly cause that sound when 4x4 is activated.