Piston Ring: Service and Repair

Piston Rings

Removing






- Remove the piston and connecting rod. Refer to => [ Piston and Connecting Rod ] Removal and Replacement.

- Remove the number 1 and number 2 piston rings from the piston using a piston ring expander.

- Remove the upper oil ring side rail.

- Remove the lower oil ring side rail.

- Remove the oil ring expander.

Installing






- Measure the clearance of the piston rings to the cylinder bore and piston. Refer to => [ Piston, Pin and Ring Specifications ] [1][2]Piston, Engine.

The number 1 (1) and number 2 (2 and 3) piston rings have a different cross section. Ensure that which ever design number 2 ring ( 2 or 3) is installed, it is installed with the manufacturers ID mark (dot) facing up, towards the top of the piston.

- Install the piston rings to the piston in the following order:

• Oil expander ring.

• Lower oil ring side rail.

• Upper oil ring side rail.

• Number 2 piston ring.

• Number 1 piston ring.








- Install the oil ring side rail (1) by placing one end between the piston ring groove and the oil expander ring. Hold the end firmly and press down the portion to be installed until the oil ring side rail is in position. Do not use a piston ring expander during this step.






The number 1 and number 2 piston rings have a different cross section. Ensure that when the number 2 ring is installed, it is installed with the manufacturers ID mark (dot) facing up, towards the top of the piston.

- Install the upper side rail first and then the lower side rail.

- Install the number 2 piston ring and then the number 1 piston ring.






- Position the piston ring end gaps (1, 2, 4 and 5).

- Position the oil ring expander gap at least 45 degrees from the side rail gaps but not on the piston pin center (3) or on the thrust direction. Staggering the ring gap is important for oil control.

- Install the piston and connecting rod. Refer to => [ Piston and Connecting Rod ] Removal and Replacement.