I use Lucas hypoid gear oil which is available at auto zone are advanced auto parts. Just look for gear oil and go look at the Lucas products and read and it will say for use in hypoid gear oil and that is what you use its 10 bucks but it is not bad as for my oil changes all I use is AM oil. It is the best gn4 does not do it for me a new plug every ride and oil change every three drive me mad though my bike runs perfect. It is a 2004 450 foremen 4x4 good luck and run synthetic through your bike and proves to be long lasting. I put exhaust and a uni filter Mud Lite XTR 27 which the bike rather eats.
Tags: 2004, 450, consumption, Foreman, honda, oil