Measure 1 . Piston pin diameter. Check against “Specifications.” 2 . Piston pin-to-piston clearance. A . Measure the piston pin hole diameter. B . Subtract the piston pin diameter from the piston pin hole diameter to obtain the clearance. C . Replace the piston and piston pin if the clearance exceeds specifications. The piston and piston pin are a matched set and not available separately. Figure 12-30 Removing Piston Rings 4 . Piston. • Ring land for cracking, wear, etc. • Ring grooves for burrs, nicks, etc. • Skirts and pin bosses for cracking. • Skirts for scuffing. 5 . Connecting rod bearing inserts for scratches or deep pitting.
Figure 12-32 Measuring Piston Pin Diameter Figure 12-31 Removing Piston Pin Measuring Piston Pin-To-Piston Clearance Figures 12-32 and 12-33 Figure 12-33 Measuring Piston Pin Bore Diameter G643 (E) Service Manual Chapter 3. Engine Mechanical System 77