4wd making odd noises

[rolfsent]

The 4wd on my 99 Denali makes an odd whining/howling/turbine sound that comes from the front end. The front wheels will engage and disengage without a problem. It makes this whining noise in all modes 4hi, 4lo and Auto4wd but not at all in 2wd. Can somebody point me in the right direction on what to start checking?

 

[SunlitComet]

Right side output shaft or carrier bearings or shifting assembly in the front diffy.

 

[rolfsent]

Right side output shaft or carrier bearings or shifting assembly in the front diffy.

Forgot to mention it will only whine if the truck is accelerating, the noise is not really there if I'm just coasting.

 

[SunlitComet]

just wear on the gears likely.

 

[rolfsent]

just wear on the gears likely.

Okay, so how do I test all those parts you said to check? Or should I just take it somewhere to get checked out?

 

[SunlitComet]

the diify or tcase needs to be opened up.