Piston & Rod Assembly
WARNING: This page is about a different car, the 2000 Lexus SC 300, 2000 Lexus GS 300, 1999 Lexus SC 300, and 1999 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
- Ensure connecting rod and connecting rod cap are marked with matching cylinder number for reassembly reference. Note direction of piston installation on connecting rod. See Fig 1.
- When removing piston from connecting rod, remove snap rings from piston. Heat piston to 176°F (80°C) in water. Remove piston pin. Separate piston from connecting rod.
- Using caliper, measure connecting rod bolt diameter .79" (20.0 mm) down from bottom of bolt head. Replace connecting rod bolt if outside diameter is less than .315" (8.00 mm).
- Ensure piston pin diameter is within specification. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS.
- Ensure connecting rod pin bushing bore diameter, crankpin bore diameter, bend and twist are within specification. See CONNECTING RODS table under ENGINE SPECIFICATIONS.NOTE: Crankpin bore diameter is identified by size mark ("1", "2" or "3") stamped on connecting rod cap. See Figure.
- Bushing in connecting rod can be replaced if bore diameter is not within specification. Ensure bushing oil hole aligns with connecting rod oil hole. Bushing must be honed to obtain correct piston pin-to-rod clearance. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS.NOTE: With piston at 176°F (80°C), it should be possible to press piston pin into piston with thumb pressure. Replace piston if pin can be pressed in with piston at room temperature.
- To reassemble, install piston with front mark on top of piston and connecting rod aligned. See Fig 1. Install NEW snap ring in piston. Ensure ends of snap ring are not aligned with piston pin cut-out area on piston.
- Heat piston to 176°F (80°C) in water. Coat piston pin with engine oil. Install piston pin and remaining NEW snap ring. Ensure ends of snap ring are not aligned with piston pin cut-out area on piston.