Help on a transfer case

[WildBill]

So I have a squeeling noise that just started. It happens under light accelleration at low RPM. if i let off the gas or accellerate hard, the noise is gone.

I got under the it and removed the rear drive shaft from the rear end. The rear end is quiet. With the tranny in neutral, engine off, I can turn the rear drive shaft (still disconnected from the rear end) slowly by hand I can hear the squeel coming from near the transfer case, possibly near the rear of the tranny.

If i remove the rear drive shaft from the transfer case, there is no play in the Transfer case output shaft. The Transfer case has the proper fluid level and works good, as does the tranny.

Any suggestions, similar issues, known problems like this.
All help is appreciated!

 

[GM-MAN]

Hard to hear over the internet, but
a popular failure on the NVG 246-263 trans cases is a pump rub issue that causes a anti wear clip to come loose and wear thru the case

Possibe you are hearing that?

 

[WildBill]

Does the pump in the T-case make noise when it starts rubbing?

 

[GM-MAN]

Not usually, it's not the pump that fails
it's a metal U shaped clip, that fits in the backside of the case. The banging causes the clip to break, then the pump wears thru the case
there are some good writeups in here

Not saying this is your problem, but a popular one

http://www.youtube.com/watch?v=afmcNkgKuMY

 

[WildBill]

Any idea on what a bad bearing in the T-case sounds like?

 

[GM-MAN]

The bearings rotate at the same speed of the wheels and when bearings fail, usually by bearing pitting , which causes rumbling low pitch noises
Squealing would most likely be from drying out, which you said you had propper fluid level

Are you sure it is in that area.
Alot of times, Serp and AC idler pulleys emit that squeek that is hard to tell where is at

 

[WildBill]

its the T-case. i can reproduce the squeel by rotating the driveshaft (unbolted from the diff) by hand with the truck off.

(I thought it was belt at first)

 

[tenntahoe]

Were you ever able to determine the cause of this noise? Mine is doing the same thing. Just started so I'm hoping it hasn't done any major damage.