Eaton Tru-Trac differential

Some You Tube videos people say they are noisy at slow speeds during tight turns.Mine did.
I had a used, complete 3.23 rear from a member about 10 years ago.It did make noise as stated above.
Maybe it was me being paranoid. I am sure it was fine only being a street car.
Several people said use straight 90 or 140 gear oil .I went with 140. Quiet now.