Piston: Service and Repair

PISTON & CONNECTING ROD

REMOVAL

NOTE: Cylinder Head must be removed before Pistons and Rods.

1. Remove top ridge of cylinder bores with a reliable ridge reamer before removing pistons from cylinder block. Be sure to keep tops of pistons covered during this operation.





2. Pistons have a directional stamping in the front half of the piston facing towards the front of engine (Fig. 60).
3. Remove oil pan.
4. Remove Balance Shaft Carrier Assembly.





5. Using a permanent ink or paint marker, identify cylinder number on each connecting rod cap (Fig. 61).

CAUTION: DO NOT use a number stamp or a punch to mark connecting rods. Damage to connecting rod could occur.

6. Remove connecting rod bolts and cap. Care should be taken not to damage the fracture rod and cap surfaces.

NOTE: Do not reuse connecting rod bolts.

7. Pistons and connecting rods must be removed from top of cylinder block. Rotate crankshaft so that each connecting rod is centered in cylinder bore.
8. Push piston and rod assembly out of cylinder bore.

NOTE: Be careful not to nick crankshaft journals.

9. After removal, install bearing cap on the mating rod.
10. Repeat procedure for each piston and connecting rod assembly
11. Piston and connecting rods are serviced as an assembly.

INSTALLATION





1. Before installing pistons and connecting rod assemblies into the bore, be sure that compression ring gaps are staggered so that neither is in line with oil ring rail gap (Fig. 62).
2. Before installing the ring compressor, make sure the oil ring expander ends are butted and the rail gaps located as shown in (Fig. 62). As viewed from top.





3. Immerse the piston head and rings in clean engine oil, slide the ring compressor, over the piston (Fig. 63). Be sure position of rings does not change during this operation .





4. The directional stamp on the piston should face toward the front of the engine (Fig. 60).
5. Rotate crankshaft so that the connecting rod journal is on the center of the cylinder bore. Insert rod and piston assembly into cylinder bore and guide rod over the crankshaft journal.
6. Tap the piston down in cylinder bore, using a hammer handle. At the same time, guide connecting rod into position on connecting rod journal.

NOTE: The connecting rod cap bolts should not be reused.

7. Before installing the NEW bolts the threads should be coated with clean engine oil.
8. Install each bolt finger tight then alternately torque each bolt to assemble the cap properly.

CAUTION: Do not use a torque wrench for second part of last step.

9. Tighten the bolts to 27 Nm PLUS 1/4 turn (20 ft. lbs. PLUS 1/4 turn).





10. Using a feeler gauge, check connecting rod side clearance (Fig. 64).
11. Install Balance Shaft Carrier Assembly.
12. Install oil pan.
13. Install cylinder head.