FUSO 4M4 – Engine – ON-VEHICLE INSPECTION AND ADJUSTMENT – Inspection and Adjustment of Valve Clearance

• Valve clearance should be checked and adjusted as follows while the engine is still cold.

• Remove the rocker cover.

• Bring the No. 1 or No. 4 cylinder piston to the top dead center (TDC) on the compression stroke according to the following procedure:

• Rotate the crankshaft pulley in the illustrated direction so that the notch on the crankshaft pulley is aligned with the “0” mark on the timing gear case.

• This will place either the No. 1 or No. 4 cylinder piston at TDC on the compression stroke. When the protrusion on the camshaft is facing upward the No.1 piston is at TDC. Rotate the engine by one full turn to switch the TDCs of the No. 1 and No. 4 cylinder pistons.

• With the No. 1 or No. 4 cylinder piston at TDC, measure the clearance of the valves marked with a circle in the table below.

• The feeler gauge must have a slight drag when taking measurements.
• If the feeler gauge can be moved without any resistance, the measurement will be incorrect.
• If the measurements are not within the standard value range, adjust the valve clearance via the following procedures.

• For valve clearance adjustment, loosen the lock nut and turn the adjusting screw so that the feeler gauge moves with some resistance.
• After the adjustment, hold the adjusting screw in place with a screwdriver and tighten the lock nut to the specified torque. Inspect the valve clearance again with the feeler gauge.
• After the inspection, install the rocker cover and the gasket. (See later sections.)


Leave a Reply

Your email address will not be published. Required fields are marked *