C-10 and C-12 Truck Engines Caterpillar

Illustration 1	g01416650

(1) The piston is symmetrical with a center crater. Lubricate the entire piston in zone (A) prior to assembly into the cylinder block. Use clean engine oil.

Top Piston Ring (2)

Install the piston ring with the side marked "UP-1" toward the top of the piston. The green stripe faces to the right of the piston ring end gap.

When a new piston ring is installed in a cylinder liner with a bore of 130 mm (5.1 inch), the clearance between the ends of the piston ring is the following value: ... 0.515 ± 0.125 mm (0.0203 ± 0.0049 inch)

Increase in clearance for the piston ring ... 0.03 mm (0.001 inch)

Increase in the cylinder liner bore ... 0.09 mm (0.004 inch)

Minimum depth of the groove in new piston for the top ring ... 5.43 mm (0.214 inch)

Thickness of new top piston ring ... 3.93 mm (0.155 inch)

Intermediate Piston Ring (4)

Install the piston ring with the side marked "UP-2" toward the top of the piston. The red stripe faces to the right of the piston ring end gap.

Width of groove in new piston for intermediate piston ring ... 3.052 ± 0.013 mm (0.1202 ± 0.0005 inch)

Minimum depth of groove in new piston for intermediate piston ring ... 5.43 mm (0.214 inch)

Thickness of new intermediate piston ring ... 2.950 ± 0.013 mm (0.1161 ± 0.0005 inch)

Clearance between groove and intermediate piston ring ... 0.076 to 0.128 mm (0.0030 to 0.0050 inch)

When a new piston ring is installed in a cylinder liner with a bore of 130 mm (5.1 inch), the clearance between the ends of the piston ring is the following value: ... 0.65 ± 0.10 mm (0.026 ± 0.004 inch)

Increase in clearance for the intermediate piston ring ... 0.03 mm (0.001 inch)

Increase in the cylinder liner bore ... 0.09 mm (0.004 inch)

Oil Control Piston Ring (5)

The ends of the oil control piston ring should be a distance of 180 degrees from the ring end gap when the oil control piston ring is assembled. The white colored portion of the piston ring must be visible at the ring end gap.

Width of groove in new piston for oil control piston ring ... 4.042 ± 0.012 mm (0.1591 ± 0.0005 inch)

Minimum depth of groove in new piston for oil control piston ring ... 3.727 mm (0.1467 inch)

Thickness of new oil control piston ring ... 3.980 ± 0.010 mm (0.1567 ± 0.0004 inch)

Clearance between groove and oil control piston ring ... 0.030 to 0.080 mm (0.0012 to 0.0031 inch)

When a new piston ring is installed in a cylinder liner with a bore of 130 mm (5.1 inch), the clearance between the ends of the piston ring is the following value: ... 0.45 ± 0.15 mm (0.018 ± 0.006 inch)

Increase in clearance for the piston ring ... 0.03 mm (0.001 inch)

Increase in the cylinder liner bore ... 0.09 mm (0.004 inch)

After the piston rings have been installed, rotate the piston rings so that the end gaps are 120 degrees from each other.

Piston Pin Bore (6)

Note: Thoroughly lubricate the piston pin with clean engine oil prior to assembly.

Bore in piston skirt (7) for the piston pin ... 53.190 ± 0.005 mm (2.0941 ± 0.0002 inch)

Bore in the piston crown assembly (3) for the piston pin ... 53.205 ± 0.010 mm (2.0947 ± 0.0004 inch)