How to Change the Gear Shaft on a Polaris Jet Ski

The gear shaft, also called drive shaft, on the Polaris jet ski is a vital part of the personal water craft's propulsion system. The gear shaft connects to the engine and turns the water pump's impeller, which forces water to flow throughout the engine. The circulation of water keeps the engine from overheating during use. If the drive shaft ever becomes uncentered, bent or otherwise damaged, it will have to be replaced.

Things You'll Need

  • Adjustable wrench
  • Phillips screwdriver
  • Socket set
  • Siphon and hand pump
  • Open end wrench
  • Spline socket
  • Fresh gear oil
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Instructions

    • 1

      Lift the engine cover off and remove the negative battery cable with an adjustable wrench.

    • 2

      Remove the plastic power take off (PTO) cover by unscrewing the wing nuts by hand and lifting off the cover.

    • 3

      Use the socket set to remove the reverse throttle cable and then remove the hose screws with a Phillips screwdriver. Pull the hoses from the water pump housing.

    • 4

      Remove the gear box drain plug with a socket set. Insert the end of a hand siphon pump and pump the oil from the gear box. Pump the oil into a drip pan for disposal. Screw the drain plug back on by hand.

    • 5

      Remove the water pump housing retaining bolts with the socket set and then slide the pump off the drive shaft.

    • 6

      Slip an open-end wrench over the pinion nut at the base of the drive shaft with one hand. With the other hand, grasp the drive shaft with a spline holding socket and turn the drive shaft to the right to remove it. Insert the new drive shaft and tighten it with spline holding socket.

    • 7

      Slip the water pump assembly back over the new drive shaft, align it by hand and then tighten the retaining bolts with the socket set.

    • 8

      Unscrew the gear oil plug and then use the hand pump to fill the gear box with fresh oil.

    • 9

      Reattach hoses to the water pump and tighten them with the screwdriver.

    • 10

      Replace the reverse throttle cable with the socket set and then set the PTO cover back in place and replace the wing nuts.

    • 11

      Replace the negative battery cable with the wrench and then put the engine cover back into position.