PLATE 8H5124 - Caterpillar

Illustration 1 g03017416
Table 1
Specification for 377-4525 Piston
Item Qty Part Specification Description
Before assembly of the piston rings, lubricate the ring grooves with clean engine oil.
1 1 229-1632 Piston Ring Install with side marked “UP-1” toward top of the piston.
Thickness of the new piston ring is 4.5 mm (0.18 inch).
Clearance of the ends when assembled in a new cylinder liner of bore 170 mm (6.7 inch) is 0.625 0.125 mm (0.0246 0.0049 inch).
Increase in clearance for each 0.03 mm (0.001 inch) increase in the cylinder liner bore is 0.09 mm (0.004 inch).
2 1 144-5695 Piston Ring Install with side marked “UP-2” toward top of the piston.
Thickness of the new piston ring is 3.785 mm (0.1490 inch).
Clearance of the ends when assembled in a new cylinder liner of bore 170 mm (6.7 inch) is 1.00 0.15 mm (0.039 0.006 inch).
Increase in clearance for each 0.03 mm (0.001 inch) increase in the cylinder liner bore is 0.09 mm (0.004 inch).
3 1 165-6668 Piston Ring The ends of the spring coil should be placed 180 degrees from the end gap of the oil control piston rings.
Thickness of the new piston ring is 3.980 0.010 mm (0.1567 0.0004 inch).
Clearance of the ends when assembled in a new cylinder liner of bore 170 mm (6.7 inch) is 0.65 0.15 mm (0.026 0.006 inch).
Increase in clearance for each 0.03 mm (0.001 inch) increase in the cylinder liner bore is 0.09 mm (0.004 inch).
Width of the groove (A) in the piston is 4.055 0.015 mm (0.1597 0.0006 inch).
4 1 376-8090 Piston Lubricate the entire piston to 360 degrees prior to assembly into the cylinder block. Use clean engine oil.
5 1 302-3451 Piston Pin Thoroughly lubricate the piston pin with clean engine oil prior to assembly.
Diameter is 69.930 0.005 mm (2.7531 0.0002 inch).
Bore of the bushing (B) for piston pin is 70.0705 0.0075 mm (2.7587 0.0003 inch).
Bore for bushing in the piston is 75.990 0.010 mm (2.99173 0.0004 inch).
6 2 253-1238 Pin Retainer Install the pin retainer with the opening towards top of the piston as shown in Illustration 1.
After installing the piston rings, rotate the piston rings so that the end gaps are placed at 120 degrees distance from each other.