Oil
Postmaster
Joined: Dec 2002
Posts: 3,959
Likes: 9
From: USA
What oil you need depends on what transfer case you have. If you have a part-time gear-drive iron-case NP205, it uses gear oil. 90wt will do fine. Other iron gear-drive cases, like the Dana 20, 21, and 24 t-cases, also use gear oil. The NP203 iron full-time chain-drive t-case uses 10-40 motor oil, if I remember correctly (been a few years since I had an NP203). Most later model aluminum chain drive t-cases use tranny fluid.
