Hey guys im working on a 1988 yamaha big bear 350 4x4, i am replacing the transfer case becasue its cracked. My question is what kind of oil does it take, and do i fill it up to that plug on the side of the case. also where the transfer case bolts up to the back of the engine there is a cover that has a plug which houses 2 gears, what oil goes in there or does the motor fill them both up??? any info would be appreciated...