Camshaft: Testing and Inspection

INSPECT CAMSHAFTS AND BEARINGS.

1. Inspect camshaft for runout
a. Place the camshaft on V-blocks.
b. Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.04 mm (0.0016 in.)

If the circle runout is greater than maximum, replace the camshaft.





2. Inspect cam lobes
Using a micrometer, measure the cam lobe height.

Standard cam lobe height:
Intake: 35.310-35.410 mm (1.3902-1.3941 in.)
Exhaust: 35.560-35.660 mm (1.4000-1.44039 in.)

Minimum cam lobe height:
Intake: 35.20 mm (1.3858 in.)
Exhaust: 35.45 mm (1.3957 in.)

If the cam lobe height is less than minimum, replace the camshaft.






3. Inspect camshaft journals
Using a micrometer, measure the journal diameter.
Journal diameter: 26.959-26.975 mm (1.0614-1.0620 in.)
If the journal diameter is not as specified, check the oil clearance.






4. Inspect camshaft bearings
Check that bearings for flaking and scoring. If the bearings are damaged, replace the bearing caps and cylinder head as a set.

NOTE: Camshaft bearings are part of the cylinder head assembly and not separate from the head.





5. Inspect camshaft gear spring
Using a vernier caliper, measure the free distance between the spring ends.

Free distance: 22.5-22.9 mm (0.886-0.902 in.)

If the free distance is not as specified. replace the gear spring.





6. Inspect camshaft journal oil clearance
a. Clean the bearing caps and camshaft journals.
b. Place the camshafts on the cylinder head.
c. Lay a strip of Plastigage across each of the camshaft journals.





d. Install the bearing caps.
Torque: 19 Nm (14 ft lb)

NOTE: Do not turn the camshaft.





e. Remove the bearing caps.





f. Measure the Plastigage at its widest point.
Standard oil clearance: 0.025-0.062 mm (0.0010-0.0024 in.)
Maximum oil clearance: 0.10 mm (0.0039 in.)
If the oil clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set
g. Completely remove the Plastigage.





7. Inspect camshaft thrust clearance
a. Install the camshaft.
b. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

Standard thrust clearance:
Intake: 0.045-0.100 mm (0.0018-0.0039 in.)
Exhaust: 0.030-0.085 mm (0.0012-0.0033 in.)

Maximum thrust clearance:
Intake: 0.12 mm (0.0047 in.)
Exhaust: 0.10 mm (0.0039 in.)

If the thrust clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.






8. Inspect camshaft gear backlash
a. Install the camshafts without installing the exhaust cam sub-gear.
b. Using a dial indicator. measure the backlash.
Standard backlash:
0.020-0.200 mm (0.0008-0.0079 in.)
Maximum backlash:
0.30 mm (0.0188 in.)

If the backlash is greater then maximum, replace the camshafts.