03 Z71 front end noise only in 4wd
 

Hello. I have a 03 Suburban z71 that is 4wd not AWD. I have searched the forums and it seems front end noises are common in these cars.

This is my noise & Symptoms:

When the truck is in 4wd hi and driving with foot on gas I can hear a little bit of a whine or moan if I listen carefully- not too bad. Now when I let off the gas it is much more noticed - very noticeable. I have change the diff fluid to synthetic and changed the transfer case fluid at the same time. The seal on the pass side axle was leaking and I changed it and it is leaking again though but I have kept fluid in it and doesn't lose very much.

Would this be a bearing in the differential on the ends or in the gears. I was told there are bearings near the axles or the axle (CV joint) itself.

1 other thing. when the truck is in 2wd and you turn the wheel the whole way to one side it kind of feels like its in 4wd- a little bit maybe this is how its suposed to be? Its been a long time since I have driven a 4wd vehicle and this is my wifes and of course she has no idea if anything has changed.