ENGINE AR-PRIMARY 2421327 - Caterpillar

Illustration 1 g03538917
Table 1
Item Qty Part Specification Description
Install the rod and piston group in the engine with the part number of the forging for the rod assembly to the rear of the engine. The rear of the engine is the flywheel end of the engine. Lubricate the rod and piston group with clean engine oil before you insert the rod and piston group into the block.
1 1 447-5626 Piston Ring Install the top piston ring with the side marked "UP-1" toward the top of the piston. The blue colored stripe faces to the right of the ring end gap.
When the new top piston ring is installed in a cylinder liner bore with bore size of 115.025 0.250 mm (4.5285 0.0098 inch), the clearance between the ends of the piston ring is 0.40 0.10 mm (0.016 0.004 inch).
Thickness is 3.5 mm (0.14 inch).
2 1 467-1177 Piston Ring Install the intermediate piston ring with the side marked "UP-2" toward the top of the piston. The white-colored stripe faces to the right of the piston ring end gap.
When the new intermediate piston ring is installed in a cylinder liner bore with bore size of 115.025 0.250 mm (4.5285 0.0098 inch), the clearance between the ends of the piston ring is 0.90 0.12 mm (0.035 0.005 inch).
Width of groove in new piston body assembly for intermediate piston ring is 3.080 0.010 mm (0.1213 0.0004 inch).
Thickness is 2.980 0.010 mm (0.1173 0.0004 inch).
3 1 262-2891 Piston Ring The oil control piston ring has a spring that is installed with the ring. The gap in the spring should be a distance of 180 degrees from the ring end gap when the oil control piston ring is assembled. The orange colored portion can be to the right or to the left of the ring end gap.
When the new oil control piston ring is installed in a cylinder liner bore with bore size of 115.025 0.250 mm (4.5285 0.0098 inch), the clearance between the ends of the piston ring is 0.45 0.15 mm (0.018 0.006 inch).
Width of groove in new piston body assembly for oil control piston ring is 4.050 0.010 mm (0.1594 0.0004 inch).
Thickness is 3.985 0.010 mm (0.1569 0.0004 inch).
After the piston rings have been installed, rotate the piston rings so that the end gaps are 120 degrees from each other.
Thoroughly lubricate the entire piston prior to assembly into the cylinder block with clean engine oil.
4 1 524-5566 Piston Pin Thoroughly lubricate the piston pin with clean engine oil prior to assembly.
Outside diameter is 50.000 0.005 mm (1.9685 0.0002 inch).
The inside diameter is 23.4 0.3 mm (0.92 0.01 inch).
Length is 90.85 0.20 mm (3.577 0.008 inch).