Piston, Pin, and Piston Rings
- Replace pistons, pins, and connecting rods that are damaged or show signs of excessive wear.
- The piston, pin, and connecting rod are to be serviced as an assembly.
- Do not wire brush any part of the piston.
- Measurement of the components should be taken with the components at normal room temperature.
- Using cleaning solvent, clean the varnish and carbon from the piston and rod assembly.
- Dry the components with compressed air.
- Clean the piston ring grooves with a suitable ring groove cleaning tool.
- Clean the oil lubrication holes and slots.
- Inspect the piston for the following conditions:
- Cracks in the piston ring lands, the piston skirt, or pin bosses
- Piston ring grooves for nicks, burrs, or warpage which may cause the piston ring to bind
MINOR imperfections may be removed from the piston with a fine file.
- Eroded areas at the top of the piston (1)
- Scuffed or damaged skirts (2)
- Scoring to the piston pin bore (3) or piston pin
- Insert the edge of the piston ring into the piston ring groove.
Roll the piston ring completely around the piston. If binding is caused by a distorted ring groove, MINOR imperfections may be removed with a fine file. If binding is caused by a distorted piston ring, replace the rings, as required.
- Measure the piston ring side clearance with a feeler gauge. If side clearance is not within specifications, try another piston ring. If the proper ring-to-groove clearance cannot be obtained, replace the piston, pin, and connecting rod assembly. Refer to Engine Mechanical Specifications (7.0L) .
NOTE:
WARNING:
Refer to Safety Glasses Warning
.