2008 Sportsman 500 Service Manual Chapter 3

ENGINE

Crankcase Bearing Inspection Pump Shaft Oil Seal/Water Pump Mechanical

Seal Removal (Engine Disassembled)

NOTE: The water pump mechanical seal can be removed without removing the engine. Refer to Water

Pump Mechanical Seal Installation.

Replace the pump shaft seal and water pump mechanical seal whenever the crankcase is disassembled.

1.

Remove the seal from the PTO side crankcase.

2.

Inspect the crankshaft main bearings, balancer shaft bearings, and pump shaft bearing.

NOTE: Due to extremely close tolerances and minimal wear, the bearings must be inspected visually, and by feel. Look for signs of discoloration, scoring or galling.

Turn the inner race of each bearing. The bearings should turn smoothly and quietly. The outer race of each bearing should fit tightly in the crankcase. The inner race should be firm with minimal side to side movement and no detectable up and down movement.

3.

Support the crankcase and drive or press the main bearings out of each crankcase.

4.

To remove balancer shaft bearings and pump shaft bearing use a blind hole bearing puller.

NOTE: Bearings are stressed during the removal process and should not be re-used!

1.

Remove the pump shaft bearing from the Magneto (right hand) side crankcase.

2.

Pry out the oil seal, noting the direction of installation with the spring side facing IN (toward inside of case).

3.

Drive the water pump mechanical seal out of the crankcase from inside to outside. Note: The new mechanical seal must be installed after the crankcases are assembled, using a special tool. See Mechanical Seal Installation.

Crankcase Inspection

1.

Remove all traces of gasket sealer from the crankcase mating surfaces. Inspect the surfaces closely for nicks, burrs or damage.

2.

Check the oil pump and oil passage mating surfaces to be sure they are clean and not damaged.

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