Hello, I have a 1994 Yamaha big bear 350. It’s been sitting for years and want to do a service on all the oils. I am going to do the front and rear differential, and motor oil. But one thing I am confused on is the transmission. Or the final gear I’ve heard it called. I’ve also heard the motor oil and transmission is all one. Very confused. Any advice is greatly appreciated !
thank you

 

Yes, the crankcase and transmission share the same oil. I believe mine (1989) is like 3.7 quarts including filter I don’t think yours is different. Use an oil that is compatible for use with the wet clutch. I pulled the drain bolt on the front driveshaft tail housing (rear of motor housing just in front of the left rear wheel) as well as disconnected the oil cooler lines just to get every last bit of oil out especially if it’s been sitting that long. May not be necessary but I’d rather get as much out as possible and start fresh.

The final gear oil oil refers to the rear axle gear oil. I believe it’s 80w90.

Do yourself a favor and search for an owners manual online they are pretty easy to find and have a lot of tune up info that you’ll be needing (spark plug gap, valve clearances, capacities, etc.)

 

Thank you for the help! Makes more sense now, I will definitely be buying a owners manual also. Thanks again!

 

For clarification, the drain bolt for the front driveshaft portion of the motor/transmission housing is below the left side rear swing arm pivot. you'll need to remove the rear most skid plate. Also, you don't have to remove the oil cooler lines. When you pull the engine oil filter housing just pull the lines down and let gravity drain the oil out, it may help to remove the little clip that holds the supply/return lines to the frame (underneath the stator cover).