Rocker Arm Assembly: Service and Repair

REMOVAL AND INSTALLATION

REMOVAL SERVICE POINT





Rocker Arm And Rocker Arm Shaft Removal
(1) Before removing the rocker arm and rocker arm shaft, mount special tools to prevent the lash adjusters from slipping off.

INSTALLATION SERVICE POINTS

Camshaft Installation





(1) Apply engine oil to the camshaft journals and cams, and then install the camshafts.
Use care to prevent confusion of the right and left bank camshafts.

NOTE The right bank camshaft is identified by a slit 4 mm (0.17 inch) wide at the rear end of the camshaft.





(2) Check to see that the dowel pin of the camshaft is located at the position shown.

Lash Adjuster Installation





(1) Immerse the lash adjuster in clean diesel fuel.
(2) Using the special tool (air bleed wire), move the plunger up and down 4 or 5 times while pushing down lightly on the check ball in order to bleed out the air.





(3) Insert the lash adjuster to rocker arm, being careful not to spill the diesel fuel. Then use the special tool to prevent the adjuster from falling while installing it.

Rocker Arm, Rocker Shaft And Rocker Shaft Spring Installation





(1) Temporarily tighten the rocker shaft with bolts at the condition that all the intake valve rocker arms do not push the valves.
(2) Insert the rocker shaft spring from above and mount it at right angles to the plug guide.

NOTE Before installing the exhaust rocker arms and rocker arm shaft, mount the rocker shaft spring.





(3) Remove the special tools used to hold the lash adjusters in position.
(4) Check ensure that the flat side of the rocker shaft is directed as shown in the illustration.








Camshaft Oil Seal Installation

INSPECTION





Camshaft
Measure cam height (longer diameter of the cam). If it exceeds the limit, replace the camshaft.

Standard value:
Intake side 37.58 mm (1.4795 inch)
Exhaust side 36.95 mm (1.4547 inch)

Limit:
Intake side 37.08 mm (1.4598 inch)
Exhaust side 36.45 mm (1.4350 inch)

Lash Adjuster Leak Down Test

Caution
1. The lash adjuster is a precision part. Keep it free from dust and other foreign matters.
2. Do not disassemble the lash adjusters.
3. When cleaning the lash adjusters, use clean diesel fuel only.





(1) Immerse the lash adjuster in clean diesel fuel.





(2) While lightly pushing down inner steel ball using the special tool (Air bleed wire MD998442), move the plunger up and down four or five times to bleed air.
Use of the special tool (Retainer MD998441) helps facilitate the air bleeding.
(3) Remove the special tool (Air bleed wire MD998442) and press the plunger. If the plunger is hard to push in, the lash adjuster is normal. If the plunger can be readily pushed in all the way, bleed the lash adjuster again and test again. If the plunger is still loose, replace the lash adjuster.

Caution: Upon completion of air bleeding, hold lash adjuster upright to prevent inside diesel fuel from spilling.

(4) After air bleeding, set the lash adjuster on the special tool (Leak down tester MD998440).
(5) After the plunger has gone down somewhat 0.2 - 0.5 mm (0.008 - 0.020 inch), measure the time taken for it to go down 1 mm (0.04 inch). Replace if the measured time is out of specification.

Standard value: 4 - 20 seconds/1 mm (0.04 inch)
[Diesel fuel at 15 - 20°C (50 - 68°F)]