How to Change Suzuki Boulevard M90 Final Drive Oil 

You change your Suzuki motorcycle’s engine oil frequently enough, but what about the rear differential (final drive) oil? 

Changing the rear diff fluid on a Suzuki motorcycle is just as easy as changing the motor oil, as both oil service maintenance tasks can be done in a matter of minutes. Watch the video above and follow the steps below to do a Suzuki Boulevard M90 final drive oil change.

Tools and Supplies – Suzuki M90 Rear Diff Fluid Change

• Ratchet
• 17mm, 21mm sockets
• Torque wrench
• Drain pan
• 80W90 hypoid oil

Changing Suzuki Boulevard Differential Oil

Step 1. Position a drain pan under the rear differential.

Step 2. Remove the 17mm oil fill plug and the O-ring from the rear differential. Inspect the O-ring for damage and replace it if necessary.

Step 3. Remove the 21mm oil drain plug and the crush washer from the rear differential. Inspect the crush washer for wear, and replace it if necessary.

Step 4. Drain out the old differential oil, then reinstall the crush washer and drain bolt, and torque the bolt to 18 foot-pounds.

Step 5. Fill the rear diff with 7.4 ounces of 80W90 hypoid gear oil.

NOTE: 7.4 ounces is the point at which the oil will begin to overflow from the diff fill hole.

Step 6. Reinstall the O-ring and fill plug into the rear differential, and torque the bolt to 18 foot-pounds.

Step 7. Clean away any excess oil from the rear differential and the wheel using contact/brake cleaner and you’re done. 

If you changed the differential oil on your Suzuki M90 but haven’t changed the engine oil, why not do that now? Watch the video below to see how to change the oil on a Suzuki M90 Boulevard.