- Yamalube 4 10W-40.
For the 1998 Grizzly 400 Differential, the recommended gear oil is:
- Yamalube Gear Oil.
For the 1998 Grizzly 400 Chaincase, the recommended chaincase oil is:
- Yamalube Chaincase Oil.
Note: Always refer to the owner's manual for the specific oil type and viscosity recommended for your particular Yamaha Grizzly 400 model and usage conditions.