Piston: Service and Repair

DISASSEMBLY

NOTE: Mark the pistons to ensure assembly with the original connecting rods and installation in the same cylinders from which they were removed.






1. Remove the piston rings from the piston and discard.
1 Remove the two compression rings.
2 Remove the two oil control ring segments and the spacer.


WARNING: THE RETAINING RING HAS A TENDENCY TO SPRING OUT DURING REMOVAL. COVER THE END OF THE PIN BORE WITH A HAND OR SHOP RAG WHEN REMOVING THE RETAINING RING. EYE PROTECTION SHOULD BE WORN. FAILURE TO FOLLOW THESE INSTRUCTION WILL RESULT IN PERSONAL INJURY.






2. Use an O-ring Tool and remove the two piston pin retaining rings.





3. Gradually heat the piston to approximately 70-130°C.
4. Use a Piston Pin Remover/Replacer and push the piston pin from the piston and connecting rod.

ASSEMBLY
1. Clean and inspect the piston and connecting rod.

NOTE: Check each end of the piston pin for an identification mark. If present, install the piston pin with the identification mark toward the front of the engine.






2. Install a new piston pin retainer ring into one side of the piston pin bore.





3. Gradually heat the piston to approximately 70-130°C.

NOTE: Tap the pin lightly with a plastic mallet if necessary.






4. Lubricate and start the piston pin in the piston and connecting rod.
5. Use a Piston Pin Remover/Replacer and push the piston pin through the piston until it bottoms on the retaining ring.





6. Install a new piston pin retaining ring on the opposite side of the piston pin bore.
- Ensure that the connecting rod moves freely after assembly.

NOTE:
- Install piston rings from top side of piston. Avoid scratching the Teflon coating on piston skirts if present.
- Assemble scraper groove down on lower compression ring.
- Orient the oil control ring spacer so the cut ends are pointed toward the piston dome.





7. Install the piston rings.
1 Use a Piston Ring Expander and install the two compression rings.
2 Install the two oil control ring segments and spacer.

8. Check the end gap of all piston rings.





9. Position the compression rings, oil control rings and expander gaps.
1 Locate the oil control segment ring gap.
2 Locate the expander ring and lower compression ring gaps.
3 Locate the upper compression ring gap.