EDGE-CUTTING 4T2948 - Caterpillar

Illustration 1 g01481993 (1) The piston is symmetrical with a center crater. Lubricate the entire piston to 360 degrees in zone (A) prior to assembly into the cylinder block. Use clean engine oil.Top Piston Ring (2)
Note: Install the top piston ring with the side marked "UP-1" toward the top of the piston.Thickness of the new top piston ring ... 4.0 mm (0.16 inch)Clearance between the ends of the piston ring in a cylinder liner bore of 130.000 mm (5.1181 inch) ... 0.40 0.10 mm (0.016 0.004 inch)Increase in the clearance between the ends of the piston ring for each 0.03 mm (0.001 inch) increase in the cylinder liner bore ... 0.09 mm (0.004 inch)Intermediate Piston Ring (3)
Note: Install the intermediate piston ring with the side marked "UP-2" toward the top of the piston.Width of groove in new piston for intermediate piston ring ... 3.053 0.013 mm (0.1202 0.0005 inch)Thickness of the new intermediate piston ring ... 2.980 0.010 mm (0.1173 0.0004 inch)Clearance between the ends of the piston ring in a cylinder liner bore of 130.000 mm (5.1181 inch) ... 1.000 0.125 mm (0.0393 0.0049 inch)Increase in the clearance between the ends of the piston ring for each 0.03 mm (0.001 inch) increase in the cylinder liner bore ... 0.09 mm (0.004 inch)Oil Control Ring (4)
Note: 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 ... 4.052 0.012 mm (0.1595 0.0005 inch)Thickness of the new oil control ring ... 3.980 0.010 mm (0.1567 0.0004 inch)Clearance between the ends of the piston ring in a cylinder liner bore of 130.000 mm (5.1181 inch) ... 0.45 0.15 mm (0.018 0.006 inch)Increase in the clearance between the ends of the oil control ring for each 0.03 mm (0.001 inch) increase in the cylinder liner bore ... 0.09 mm (0.004 inch)Note: After the piston rings have been installed, rotate the piston rings so that the end gaps are 120 degrees from each other.Piston Pin (5)
Note: Thoroughly lubricate the piston pin with clean engine oil prior to assembly.Piston pin bore diameter ... 53.220 0.010 mm (2.0952 0.0004 inch)