Camshaft: Service and Repair

1. Remove timing belt as described under ``Timing Belt, Replace.''
2. Remove camshaft sprocket attaching bolt, sprocket and dowel pin. Use a screwdriver or other suitable tool to prevent sprocket from turning when removing attaching bolt.
3. Remove cylinder head as described under ``Cylinder Head, Replace.''
4. Remove rocker arm arm shaft assemblies as described under ``Rocket Arm Service.''
5. Remove camshaft thrust plate, then remove camshaft from cylinder head.
6. If necessary, remove camshaft front seal from bore.

7. Check camshaft as follows:

Fig. 11 Measuring camshaft lobe height:

a. Check camshaft lobe height, Fig. 11. Camshaft lobes should measure 1.4378 to 1.4437 inch. If any lobe measures less than 1.4329 inch, replace camshaft.

Fig. 12 Measuring camshaft journal diameters:

b. Measure front and rear camshaft bearing journals, Fig. 12. Front and camshaft bearing journals should measure between 1.7103 to 1.7112 inch.
c. Measure center camshaft bearing journal, Fig. 12. Center camshaft bearing journal should measure 1.70791 to 1.71000 inch.
d. Measure front seal contact surface Fig. 12. Front seal contact surface should measure 1.1796 to 1.1811 inch.
e. Check all camshaft bearing journals for out of round. The out of round limit is .002 inch.
f. Measure fuel cam height, Fig. 12. Fuel pump cam height should be between 1.331 to 1.346, with a limit of 1.323 inch.

Fig. 13 Checking camshaft for straightness:

g. Check camshaft for bend condition, Fig. 13. The limit at the center journal is .0012 inch.

Fig. 14 Checking camshaft endplay:

h. Position camshaft and thrust plate in cylinder head and measure camshaft endplay, Fig. 14. Endplay should be .002 to .007 inch. If endplay exceeds .008 inch, replace thrust plate or camshaft as necessary.

Fig. 15 Measuring camshaft bearing bore:

i. Check camshaft journal to bearing clearance, Fig. 15. Clearance should not exceed .006 inch.
8. Reverse procedure to install. When installing camshaft front seal use tool No. T87C-6019-A or equivalent. Torque camshaft thrust plate retaining bolt to 6 to 9 ft. lbs. Torque camshaft sprocket bolt to 36 to 45 ft. lbs.