When overhauling Bare Engine, the Isuzu Engine must be replaced at the same time as the piston pin to restore its normal fit.

The fit between the outer diameter of the Isuzu Engine and the small end hole of the connecting rod should have an interference of 0.10~0.20mm to ensure that the bushing does not rotate during operation. If the interference is too large, it will cause difficulties in pressing the bushing or even damage the bushing.

The fit between the Isuzu Engine and the small end hole of the connecting rod and the piston pin should meet the technical requirements. Pressing the new bushing into the small end hole of the connecting rod should be done on a press or a bench vise.

Before pressing in, check whether there are burrs, curling, etc. on the small end hole of the connecting rod to avoid scratching the outer cylindrical surface of the bushing. When pressing the bushing, the oil holes should be aligned to ensure smooth flow of the lubricating oil.

In order to better prevent the bushing from loosening, after pressing the bushing into the small hole of the connecting rod, the bushing can be squeezed outward with an awl to make the bushing fit tightly with the small hole.

If a piston pin with increased maintenance dimensions is used or the bushing needs to be repaired for other reasons, the bushing should be machined to ensure that the piston pin and bushing are properly matched and the fitting clearance between the piston pin and bushing at room temperature is 0.003~0.008mm.