Piston Ring Replacement

Piston Ring Replacement

1. Remove the pistons from the engine block Crankshaft and Piston Removal.

2. Using a ring expander (A), remove the old piston rings (B).





3. Clean all the ring grooves thoroughly with a squared-off broken ring, or a ring groove cleaner with a blade to fit the piston grooves. File down the blade, if necessary. The top ring and second ring grooves are 1.2 mm (0.05 in) wide, and the oil ring groove is 2.0 mm (0.08 in) wide. Do not use a wire brush to clean the ring grooves, or cut the ring grooves deeper with the cleaning tool.

NOTE: If the piston is to be separated from the connecting rod, do not install new rings yet.

4. Using a piston, push a new ring (A) into the cylinder bore 15-20 mm (0.6-0.8 in) from the bottom.






5. Measure the piston ring end-gap (B) with a feeler gauge:

- If the gap is too small, check to see if you have the proper rings for your engine.
- If the gap is too large, recheck the cylinder bore diameter against the wear limits Testing and Inspection.

6. J35Z6 engine: If the bore is over the service limit, the engine block must be rebored.

J35Z6 engine










Second Ring:





Oil Ring:





J37A4 engine










Second Ring:





Oil Ring:





7. Install the rings as shown. The top ring (A) has a 1D mark (J35Z6 engine) or 1E mark (J37A4 engine) and the second ring (B) has a 2X mark (J35Z6 engine) or 2E mark (J37A4 engine). The manufacturing marks (C) must be facing upward.






8. After installing a new set of rings, measure the ring-to-groove clearance:

J35Z6 engine










J37A4 engine













9. Rotate the rings in their grooves to make sure they do not bind.

10. Position the ring end gaps as shown: