Measure the cam follower bores in the cylinder head
with a telescope gage and micrometer and record the
readings. Measure the diameter of the cam followers
with a micrometer. Record the readings and compare
the readings of the followers and bores to determine the
If the push rod breaks or is damaged, the rocker arm
should be suspect. Any wear or excessive movement in
the rocker arm or clevis can put a side load on the push
rod, resulting in fracture or damage. Before replacing
the push rod, inspect the rocker arm for signs of wear or
cracking. If wear or excessive movement of the rocker
arm or clevis is noted, replace the rocker arm.
Inspect the push rods and spring seats for wear. The
current push rods have milled wrench flats and a bright
"turned" finish and the lower spring seats are serrated
Fig. 5. Cam Roller Clearances
along the push rod contact surfaces (Fig. 6).
Examine the cam follower rollers for scoring, pitting or
NOTE: When replacing a push rod or
flat spots. The rollers must turn freely on their pins.
lower spring seat, do not use a plain
Measure the total diametric clearance and side
spring seat (Fig. 6) with a current type
clearance. Install a new roller and pin if the clearances
push rod. Any other combination of
exceed those specified in Fig. 5. Cam followers
spring seat and push rod may be used.
stamped with the letter "S" on the pin, roller and follower
body are equipped with an oversize pin and roller. The
Examine the cam follower springs for wear or damage
same clearances apply to either a standard or oversize
and check the spring load. Replace a spring when a
cam follower assembly.
load of less than 172 lbs. will compress it to a length of
2.125". Use spring tester J 22738-02 to check the
Examine the camshaft lobes for scoring, pitting or flat
spots. Replace the camshaft if necessary.
Fig. 6. Comparison of Push Rods and Lower Spring Seats