INSTRUMENT GP 4738691 - Caterpillar

*Install piston ring with "UP" side toward top of piston. 7S8378 Top ring (1) has the mark "UP-1."5S6750 Intermediate Ring (2) has the mark "UP-2."**Install 9S7788 Oil Control Ring (3) with the gap in the spring 180° away from the gap in the ring. Use 5P3519 PISTON RING GROOVE GAUGE to check top and center ring grooves with straight sides. For instructions on the use of the gauge, see the GUIDELINE FOR REUSABLE PARTS; PISTONS AND CYLINDER LINERS, Form No. SEBF8001. (4) Bore in piston for pin ... 1.5011 .0002 in.(38.128 0.005 mm) Maximum permissible clearance between piston pin and bore in piston (worn) ... .002 in.(0.05 mm) When installed in the engine, the "V" mark on top of the piston must be in alignment with the "V" mark on the cylinder block.