SHOE 3B2791 - Caterpillar

(1) Top piston ring. See the Piston And Piston Rings charts.(2) Intermediate piston ring. See the Piston And Piston Rings charts.(3) Oil control ring. See the Piston And Piston Rings charts.(4) Bore in piston for pin (elliptical) Vertical ... 43.188 0.004 mm (1.7003 .0002 in)Horizontal actual vertical diameter plus ... 0.040 0.007 mm (.0016 .0003 in)Clearance between pin and bore in piston ... 0.004 to 0.022 (.00015 to .0009 in)Maximum permissible clearance (worn) ... 0.05 mm (.002 in)Pin diameter ... 43.175 0.005 mm (1.6998 .0002 in) 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.