How to align the timing belt of an Isuzu engine?
2 Answers
Slowly unscrew the positioning pin and rotate the crankshaft clockwise to turn the crankshaft approximately 270° past the "top dead center" of cylinder 1. Tighten the positioning pin-T10340 to the cylinder block with a torque of 30Nm and screw it all the way down.
Isuzu engines are quite particular about timing belts, and I've done it myself a few times. The first step is to locate the crankshaft positioning hole and lock the crankshaft position with a dedicated positioning pin, which fixes the piston at top dead center. Then, check the camshaft gears—the triangular marks on them must align with the scale lines on the cylinder head, and both camshafts need careful calibration. When installing the belt, pay special attention to the tensioner adjustment: first loosen the fixing screw, then use a spring or hydraulic tensioner to adjust to the proper tightness, ensuring the pointer falls within the standard scale range. I recommend manually turning the engine a few times while installing to confirm all marks remain aligned. Finally, remember to tighten the tensioner screw according to the torque specified in the repair manual—this torque is critical. Too loose, and the belt may slip; too tight, and the bearings may wear out. The whole process is best done with two people for better control.
