FUSO 4M4 – Engine – CAMSHAFT HOLDER AND CAMSHAFT

Assembly sequence
Follow the disassembly sequence in reverse.

Removal: Cam sprocket
• Bring the No. 1 cylinder piston to the top dead center (TDC) on the compression stroke. Make sure that the camshaft cam faces up in this position.
• After holding on the hexagonal portion of the camshaft to prevent it from turning, loosen the bolt to remove the cam sprocket.

Inspection: End play of camshaft
• Attach a dial gauge to the rear of the engine and measure end play of the camshaft.
• If the measurement exceeds the limit, replace the defective part(s).

Inspection: Camshaft
(1) Difference between major axis and minor axis
• If the measured value is below the specified limit, replace the camshaft.

(2) Bend
• Support the camshaft at its No. 1 journal and No. 5 journal. Measure the extent of bend in the camshaft at the center of the No. 3 journal.
• Turn the camshaft through one revolution. One-half of the dial indicator reading represents the extent of bend.
• If the measurement exceeds the specified limit, replace the camshaft.

(3) Oil clearance at the journals
• Measure the oil clearance, and if the measured value is higher than the limit, replace the faulty parts.

•Inspection: Clearance at the rocker (roller) in the radial direction
If the measured value is not within the standard value range, replace the rocker.

Installation: Chain tensioner and gasket
• Turn the cam of the chain tensioner, push in the plunger by hand and hold it in the retracted position with the hook.
• Install the gasket on the cylinder head so that the sealant will be on the chain tensioner side.

Installation: Chain tensioner
• Install the chain tensioner, then crank the engine in the normal direction (to clockwise as seen from the front of the engine). This will undo the hook, and the ratchet mechanism inside the chain tensioner will start adjusting the tension of the timing chain.

 

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