Any 75w90 GL-5 spec fluid will work. Get this tuff because it is for LSDs and differentials, the other stuff says manual transmissions. https://www.amazon.com/Red-Line-57904-75W90-Synthetic/dp/B000CPCBF0/ref=sr\_1\_2?crid=2U8DX5Z0CIFDZ&keywords=red%2Bline%2Bgear%2Boil&qid=1666025836&qu=eyJxc2MiOiIzLjUwIiwicXNhIjoiMy4xNCIsInFzcCI6IjIuOTcifQ%3D%3D&sprefix=red%2Bline%2Bgear%2Boil%2Caps%2C236&sr=8-2&th=1