REGULATOR 2S4044 - Caterpillar

Refer to Guideline For Reusable Parts, SEBF8049, "Pistons". Refer to Guideline For Reusable Parts, SEBF8068, "Cylinder Liners". Refer to Guideline For Reusable Parts, SEBF8051, "Piston Pins And Retaining Rings".Note: The number on the tab groove side of the connecting rod is positioned toward the opposite side of the engine from the camshaft during installation.
Illustration 1 g00287964
The 1U-6431 Piston Ring Groove Gauge is necessary for measuring ring grooves in keystone style pistons. Refer to the instruction card that is included within the gauge group for the correct use of the gauge group. (1) Top piston ringThe ring should be installed with the side marked "UP-1" or "0" toward the top of the piston. (2) Intermediate ringThe ring should be installed with the side marked "UP-2" toward the top of the piston.When the piston ring is installed in a cylinder liner that has a bore size of 137.16 mm (5.4000 inch), the specific clearance between the ends of the piston ring is the following value:Top ring ... 0.724 0.190 mm (0.0285 0.0075 inch)Intermediate ring ... 1.080 0.190 mm (0.0425 0.0075 inch)For each 0.03 mm (0.001 inch) increase in the cylinder liner bore size, the clearance between the ends of the piston ring increases by 0.08 mm (0.003 inch). (3) Oil control ringThe spring ends of the oil control ring should be assembled 180 degrees from the ring end gap. The white colored portion of the spring must be visible at the ring end gap.Width of the piston groove for the new oil control ring ... 3.210 0.010 mm (0.1264 0.0004 inch)Thickness of the new oil control ring ... 3.137 0.013 mm (0.1235 0.0005 inch)Clearance between the groove and the new oil control ring ... 0.073 0.023 mm (0.0029 0.0009 inch)Maximum permissible clearance (worn) ... 0.15 mm (0.006 inch)When the piston ring is installed in a cylinder liner that has a bore size of 137.16 mm (5.4000 inch), the specific clearance between the ends of the piston ring is the following value.Oil control ring ... 0.570 0.190 mm (0.0224 0.0075 inch)For each 0.03 mm (0.001 inch) increase in the cylinder liner bore size, the clearance between the ends of the piston ring increases by 0.08 mm (0.003 inch). (4) Piston pin boreBore in piston for pin ... 55.047 0.008 mm (2.1672 0.0003 inch)Diameter of the new piston pin ... 55.000 0.005 mm (2.1654 0.0002 inch)Clearance between the pin and the bore in the piston ... 0.012 mm to 0.030 mm (0.0005 inch to 0.0012 inch)