Piston: Service and Repair

Pistons and Rods Removal and Installation

Tools Required:
J-8037 Universal Piston Ring Compressor
J-8087 Cylinder Bore Check Gauge
KM-427 Piston Pin Service Set
KM-470-B Angular Torque Gauge

Removal
1. Remove the cylinder head with the intake manifold and exhaust manifold attached.
2. Remove the oil pan.
3. Remove the oil suction pipe bolts and support bracket bolts.
4. Remove the oil suction pipe.
5. Remove the crankshaft bearing bridge and the oil pan scraper bolts.





6. Remove the crankshaft bearing bridge and the oil pan scraper.
7. Move the piston to the bottom of the piston stroke.
8. Mark the connecting rod cap for position.
9. Remove the connecting rod cap bolts.
10. Remove the connecting rod cap and the lower connecting rod bearing.
11. Remove the upper piston connecting rod bearing.





12. Ridge ream the cylinder wall.
13. Remove the piston.
14. Use a piston ring expander tool to expand the piston rings.





15. Remove the piston rings.
16. Remove the piston pin from the piston and connecting rod assembly using the piston pin service set KM-427.





17. Separate the piston from the connecting rod.

Installation

CAUTION: For ease of installation of the piston pin, the connecting rod should be heated to 280°C. Heat the upper connecting rod only. Use commercial thermocolor material to determine the correct temperature. When the thermocolor material changes from black to green, the temperature is correct for installation.

1. Align the notch on the piston and connecting rod so that the proper sides will be facing the front of the engine.
2. Install the piston pin guide through the piston and the connecting rod.
3. Coat the piston pin with clean oil.





4. Install the piston pin into the opposite side of the piston.
5. Install the piston pin into the piston and connecting rod assembly using the piston pin service set KM-427.
6. Select a set of new piston rings.
7. Measure the piston ring gap using a feeler gauge.





8. Increase the piston ring gap by carefully filing off excess material if the piston ring gap is below specifications.
9. Measure the piston ring side clearance using a feeler gauge.
10. If the piston ring is too thick, try another piston ring.





11. If no piston ring can be found that fits to specifications, the piston ring may be ground to size with emery paper placed on a sheet of glass.
12. Install a piston oil ring, the expander, then the second piston oil ring to the bottom ring groove of the piston.
13. Install the second compression ring to the middle ring groove of the piston.





14. Install the top compression ring to the top ring groove of the piston.
15. Use a piston ring expander to install the piston rings. Do not expand the piston rings beyond the expansion necessary for installation.





16. Stagger the piston oil rings, the oil ring rail gaps, the second compression ring, and the top compression ring in relation to the notch on the top of the piston.
17. Lubricate the cylinder wall and the piston rings with clean engine oil.
18. Install the piston using the universal piston ring compressor J-8037 and a wood handle. Guide the lower connecting rod end to prevent damaging the crankshaft journal.





19. Install the connecting rod cap and bearings.
20. Install the connecting rod cap bolts.
Tighten: Tighten the connecting rod bearing cap bolts to 35 Nm (26 ft. lbs.). Using the angular torque gauge KM-470-B, tighten the bolts one turn of 45° plus one turn of 15°.





21. Install the crankshaft bearing bridge/oil pan scraper bolts.
Tighten: Tighten the crankshaft bearing bridge/oil pan scraper bolts to 20 Nm (15 ft. lbs.) plus 45° using the angular torque gauge KM-470-B.
22. Install the oil suction pipe.
23. Install the oil suction pipe bolts.
Tighten: Tighten the oil suction pipe bolts to 8 Nm (71 inch lbs.) and the oil suction pipe bracket bolt to 6 Nm (53 inch lbs.).
24. Install the oil pan.





25. Install the cylinder head with the intake manifold and exhaust manifold attached.