Camshaft: Service and Repair

REMOVAL





1. Remove the cylinder head cover.





2. Remove the front bearing cap.
3. Remove the rear bearing cap.
4. Remove the bearing cap.
5. Remove the camshaft oil seal.
6. Remove the camshaft.
7. Remove the rocker arm.





8. Remove the lash adjustor.

INSPECTION

Camshaft





1. If there is excessive wear or damage on the camshaft journal or/and cam lobe after checking, replace it with a new one. Measure the height of cam and if the readings are beyond the specification, replace it.
Standard value:
Intake: 35.198 mm (1.385 inch)
Exhaust: 34.910 mm (1.375 inch)

Rocker arm
1. Inspect the roller visually, if any damage or crack is found, replace it.
2. Check that the roller rotates smoothly. If there is excessive clearance, replace it.

Leak down test of lash adjuster

Caution:
1) As the lash adjuster is a precise part, take care not to let any dust and foreign object enter.
2) Do not disassemble the lash adjuster.
3) Only light oil should be used to clean the lash adjuster

1. Immerse the lash adjuster in light oil.





2. Push out the steel ball in the lash adjuster softly using the special tool (Air bleed wire 09246-32200) and shake the plunger upward and downward 4 or 5 times. Using the special tool (09246-32100), release air from the rocker arm installation type lash adjuster.

Caution: As the ball weight is very small just a few grams), pushing the special tool excessively can damage the lash adjuster. Push it with care and appropriate force.

3. Take away the special tool (09246-32200) and push the plunger. If it feels tight, the lash adjuster is normal. If it feels soft and easy, then release air from plunger feels and test again. If the plunger feels still soft even after releasing air, replace it.

Caution: After releasing air, put the lash adjuster straight up not to spill the oil over, and make sure there is no dust or foreign material on it.

4. After finishing the air release, place the lash adjuster on the special tool (09246-32300).





5. After the plunger has gone down around 0.2 - 0.5 mm, measure the time for the plunger to go down additional 1 mm. Replace it if the time is out of standard range. Standard dropping down rate: 2 - 16.5 sec/mm (Light oil, oil temperature 20 - 30°C)

Adjustment of rocker arm clearance
1. Replace the rocker arm with the one specially made for measurement.





2. After positioning the rocker arm roller on basic circle of camshaft, push down the ball lightly with special tool (09246-32200) and push down the rocker arm by hand. Maintaining that state, measure the thickness by inserting a thickness gauge between the camshaft and rocker arm.
Clearance between camshaft (Basic circle) and rocker arm (roller): 0.7 ± 0.25 mm (0.0276 ± 0.0098 inch)

Caution: As the bail weight is very small just a few grams), pushing the special tool excessively can damage the lash adjuster. Push it with care and appropriate force.

INSTALLATION

Camshaft and bearing cap
1. Rotate the crankshaft and No.1 cylinder is in TDC (Compression stroke).
2. Check the position of the rocker arm whether it is exactly installed on the lash adjuster and valve or not.





3. Install the camshaft dowel pin as illustration.





4. The left and right banks of the camshafts are different and you should be careful not to confuse them.
Identification signal
Left bank Intake (IN) F
Exhaust (Ex) E
Right bank
Intake (IN) G
Exhaust (Ex) H





5. Confirm the identification mark and the number. Bearing caps of No.3, No.4, and No.5 have the front mark and arrange the front mark upon the cylinder head while installing the bearing caps.
Identification mark
Intake I
Exhaust E





6. Tighten the bearing cap in two or three steps. Tighten it to the standard torque at the last stage.
*Bearing cap standard torque
Torque
16 pieces at the both ends: 21 - 26 Nm (210 - 260 kg-cm, 15.49 - 19.18 ft. lbs.)
24 pieces in the middle: 10 - 12 Nm (1100 - 120 kg-cm, 7.38 - 8.85 ft. lbs.)