I have a 2000 Prairie 400 4X4 and am going to change the engine & differential oil. I don't have the owners manual. What does the owners manual call for in the diff's? Do you think 15W-40 is good for engine oil?

Thanks

 

A good brand of 80W or 90W gear oil is my recommendation for the differential. As for the engine, a good brand of 10W-30 would be my choice.

 

Don't forget that the locker in the front differential is a wet clutch pack and so is the brake in the rear end. Phone your dealer and make sure you use the correct oil or you may cause an expensive problem.

 

prairieman2000, I tried to cancel my last post but for some reason it didn't work. I'm sorry I misread your post and thought you had a 650 Prairie. As for your 400 Prairie, the service manual recommends engine oil grade SE, SF, or SG and viscosity SAE 10W-30, 10W-40, 10W-50, 20W-40, or 20W-50. They don't mention 15W-40, but as long as it is one of the grades they mention, I can't see where there would be a problem. Ask your dealer if it would still be warranted if you use the oil you want.
For the front differential they recommend API "GL-5" hypoid gear oil for limited slip differentials. Viscosity SAE140, SAE90,or SAE85-140.
For the rear end they recommend API "GL-5" hypoid gear oil. Viscosity SAE90 (above 5C or 41F) or SAE80 (below 5C or 41F).