Piston And Connecting Rod Cleaning and Inspection

Piston And Connecting Rod Cleaning and Inspection

Cleaning


DO NOT use a wire wheel or other abrasive cleaning devise to clean the pistons or connecting rods. The pistons have a Moly coating, this coating must not be damaged.


Do not remove the piston pin from the piston and connecting rod assembly.

- Using a suitable cleaning solvent clean the pistons in warm water and towel dry.

- Use a wood or plastic scraper to clean the ring land grooves.

Inspecting






- Wipe the inserts (1) clean.

- Inspect the inserts for abnormal wear patterns, scoring, grooving, fatigue, pitting and for metal or other foreign material imbedded in the lining.

- Inspect the back of the inserts for fractures, scrapes, or irregular wear patterns.

- Inspect the insert locking tabs for damage.

- Replace any bearing that shows abnormal wear. Refer to => [ Connecting Rod Bearing Replacement ] Connecting Rod Bearing Replacement.







- Inspect the connecting rod bearing bores for signs of scoring, nicks and burrs.

• Misaligned or bent connecting rods can cause abnormal wear on pistons, piston rings, cylinder walls, connecting rod bearings and crankshaft connecting rod journals. If wear patterns or damage to any of these components indicate the probability of a misaligned connecting rod, inspect it for correct rod alignment.

- Replace misaligned, bent or twisted connecting rods.

• Connecting rods are serviced with the piston pre-assembled. The pistons are "select fit" to achieve proper oil clearance.







• Typical coated piston shown.

- Inspect the piston for scoring or scraping marks in the piston skirts. Check the ring lands for cracks and/or deterioration.

- Check the piston for taper and out of round shape.

• The coating material (1 and 2) is applied to the piston after the final piston machining process. Measuring the outside diameter of a coated piston will not provide accurate results. Therefore measuring the inside diameter of the cylinder bore with a dial Bore Gauge is MANDATORY. Refer to => [ Engine Block and Cylinder Bore Inspection ] Testing and Inspection.

- Compare the measured cylinder bore diameter to the engine block cylinder bore grade marking chart. Refer to => [ Cylinder Block Specifications ] Cylinder Block Specifications. Select the piston size that corresponds to the engine block markings for each cylinder to provide the proper oil clearance.

• Piston installation into the cylinder bore requires slightly more pressure than that required for non-coated pistons. The bonded coating on the piston will give the appearance of a line-to-line fit with the cylinder bore.

• The coated pistons will be serviced with the piston pin and connecting rod pre-assembled.