Engine Mechanical - 1MZ-FE: Overhaul Toyota Highlander I

Piston & Connecting Rod Assemblies

1. Remove connecting rod bearing caps. Use a ridge reamer to remove all carbon from top of cylinder. Push piston, connecting rod and upper rod bearing through top of cylinder block (keep components together and in correct order).
2. Try to move piston back and forth on piston pin. If any movement is felt, replace piston and pin as an assembly.
3. Use piston ring expander and remove 2 compression rings. Remove 2 side rails and oil ring by hand.
4. Remove piston pin snap rings. Heat piston in liquid bath to about 140°F (60°C). With soft-face hammer and brass bar, tap out piston pin. Remove connecting rod (keep pin, rod and piston together as a set).
5. With micrometer, measure piston diameter at right angle to piston centerline. Measure cylinder bore in thrust directions. Difference between these 2 measures is piston oil clearance. See «PISTONS, PINS & RINGS»(ref-159178-S18050586182003111700000) table under ENGINE SPECIFICATIONS. If clearance exceeds specifications, replace all 6 pistons. If necessary, replace cylinder block.
6. Shape of piston varies for right and left cylinder banks. Note pistons markings for proper location. (Scheme 35)or (Scheme 36).
7. With piston heated to 140°F (60°C) piston pin should push into piston hole with hand pressure.
8. With rod aligner tool and feeler gauge, check bend of connecting rod. If connecting rod exceeds bend specification, replace connecting rod assembly. See «CONNECTING RODS»(ref-159178-S41674513772003111700000) table under ENGINE SPECIFICATIONS.
9. Check rod for twist. If twist exceeds maximum allowable specification, replace connecting rod assembly. See «CONNECTING RODS»(ref-159178-S41674513772003111700000) table under ENGINE SPECIFICATIONS.
10. With caliper, measure inside diameter of connecting rod piston pin hole bushing. With micrometer, measure piston pin diameter. Difference between these 2 measurements is piston pin oil clearance. If clearance exceeds specification, replace bushing or piston pin, as necessary. See «CONNECTING RODS»(ref-159178-S41674513772003111700000) table under ENGINE SPECIFICATIONS. When replacing bushing, be sure to align oil holes in bushing and in connecting rod.
11. Use caliper to measure outside diameter of connecting rod bolt, just above the threads. Replace connecting rod bolt if outside diameter is less than.276 in. (7.01 mm).

Scheme 35

Scheme 36