Maybe bad transfer case or diff. What to look for?

[ed1380]

Bought the car like that. 98 gsx 5sp. The only history I know is that the previous owner supposedly had the rear diff bearings changed. When driving there is a bad howling noise. Doesn't matter if accelerating, coasting, or braking. I thought it was the wheel bearings. Put the car on the lift and the wheel bearings are fine. The transmission is already off, so checking the transfer case will be easy but what are some things to look for? I drained 1/2qt of pretty clean fluid from it, so its not dry.

 

[BrokenTsi]

Ask the previous owner if the "howling" was there before the rear differential was serviced.

 

[ed1380]

The PO got the car in a trade. He knows nothing about it.