Skip to content Skip to navigation Skip to footer

2021+ 650 Switchback Assault 146 Chaincase Fluid Replacement


Tools and Supplies Required
6mm Allen SocketRatchetTorque Wrench
Fluid FillerShop RagsFluid Suction Device (Suction Method)
T40 TORX® Socket (Front Cover Method)10mm Socket (Front Cover Method)Drain Pan (Front Cover Method)
Prying Tool (Front Cover Method)Pliers (Front Cover Method)Safety Glasses & Nitrile Gloves

For more information on tools, read the Tools and Fasteners Guide.

The pump and front cover methods can be used to change the chaincase fluid on a Polaris Matryx Switchback Assault 146 with a 650 engine. Always wear safety glasses and nitrile gloves when servicing your snowmobile. 

1. Ensure the sled is on a flat, level surface.

2. Set the parking brake.

3. Clean the area around the fill plug. Placing a rag under the fill plug will help catch any escaping fluid.

4. With a 6mm Allen socket, remove the fill plug and set aside.

5. To extract the fluid using the pump method:

  • Safely elevate the front of the snowmobile using a floor jack or appropriate lift.
  • Insert the tube of the suction device into the fill hole. Direct the hose toward the bottom front area of the cover, away from the chain and sprocket.
  • Extract the oil using the suction device.
  • Then safely lower the snowmobile to fill the chaincase.

6. To drain the fluid using the front cover method:

  • Remove the right side panel by turning the three quarter-turn latches. Pivot the panel away from the sled and pull out to remove.
  • Using a T40 TORX® socket, remove the fastener on the lower right side of the console.
  • Using a pliers, remove the push rivet securing the lower right portion of the console. 
  • Remove the push rivet underneath that secures the right fender to the footrest.
  • If equipped with a battery, remove the battery and bracket.
  • Using a T40 TORX® socket, remove the two fasteners securing the lower fender to the chaincase.
  • Place a drain pan underneath the chaincase. Placing a rag in the bottom of the drain pan will help prevent the splashing of fluid.
  • With a 10mm socket, loosen but do not remove the three lower chaincase cover fasteners.
  • Carefully pry on the cover tab and allow the fluid to drain completely. DO NOT insert a screwdriver or pry bar between the cover and chaincase.
  • Reinstall the three cover fasteners. Torque to 11 ft-lbs (15 Nm). 

7. Clean any dirt or debris from the fill plug.

8. Inspect the O-ring on the plug and replace if necessary. 

9. Fill the chaincase through the fill plug hole until fluid reaches the bottom threads and begins to spill out. The fluid capacity is 10 ounces (296 ml). A 1-quart bottle of Polaris Synthetic Chaincase Lubricant is part number 2873105.

10. Reinstall the fill plug. Torque to 48 in-lbs (6 Nm).

11. Clean any residual fluid off the vehicle and dispose of the used fluid at your local recycling center.

12. If using the front cover method, continue with the following steps: 

  • Reinstall the fasteners that secure the lower fender to the chaincase. Torque to 36 in-lbs (4 Nm). 
  • If needed, reinstall the battery bracket and battery. Connect the positive cable first.
  • Reinstall the push rivet underneath the console.
  • Install the push rivet on the lower right portion of the console.
  • Reinstall the lower console fastener and torque until fully seated.
  • Reinstall the side panel by inserting the upper tab and pivoting in to engage the lower tab. 
  • Latch the three quarter-turn latches to secure the panel.

Looking for information on adjusting your drive chain tension? Read 2021+ 650 Switchback Assault 146 Drive Chain Tension Adjustment

For more information, see your authorized Polaris Dealer. To find a dealer near you, use the Dealer Locator.
Maintenance tips, procedures and specifications can be found in your Owner's Manual.
To find diagrams and replacement part numbers, use the online parts catalog.

TORX® is a registered trademark of Acument Intellectual Properties, LLC
YouTube® is a registered trademark of Google LLC

Unless noted, trademarks are the property of Polaris Industries Inc.
© 2022 Polaris Industries Inc.