DETROIT DIESEL 53
Valve Operating Mechanism 1.2.1
Inspection
Wash the rocker arms, rocker arms shaft and brackets
thoroughly in clean fuel oil and dry them with
compressed air. Make certain that the oil passages in
the rocker arms, rocker arm shaft and bracket bolts are
open and clean.
Inspect all of the parts for excessive wear.
The maximum clearance between the rocker arm shaft
and the injector rocker arm bushing or an exhaust valve
rocker arm (which has no bushing),is .004 "with used
parts.
Examine each rocker arm pallet (contact face) for wear
or galling. Also check the contact surfaces of the
exhaust valve bridge.
Remove Cam Follower and Push Rod Assembly
(Cylinder Head Removed from Engine)
With the cylinder head removed from the engine,
remove the cam followers as follows:
1. Rest the cylinder head on its side and remove the
two bolts and lock washers securing the cam follower
guide to the bottom of the cylinder head (Fig. 2).
Remove the guide.
2. Pull the cam followers from the bottom of the
Fig. 6. - Cam Follower
cylinder head.
3. Remove the fuel pipes from the injector and the fuel
1. Clean and remove the valve rocker cover.
connectors.
2. Remove the fuel pipes from the injector and the fuel
4. Loosen the lock nuts at the upper end of the push
connectors.
rods and unscrew the push rods from the rocker arm
3. Remove the rocker arm brackets and rocker arm
clevises.
shaft as outlined in Steps 3 and 4 under Remove Rocker
5. Pull the push rod and spring assemblies from ) the
Arms and Rocker Arm Shaft.
bottom of the cylinder head.
4. Loosen the lock nut at the upper end of the push rod,
6. Remove the push rod lock nut, upper spring seat,
next to the clevis, and unscrew the rocker arm from the
spring and lower spring seat from each push rod for
push rod to be removed. Remove the lock nut from the
cleaning and inspection.
push rod.
5. Install the remover J 3092-01, a flat washer and nut
The push rod spring seat retainers remain in the cylinder
on the push rod (Fig. 3). Screw the nut down on the end
head. If the head is to be changed, these retainers must
of the push rod to compress the push rod spring.
be removed and installed in the new head.
6. Remove the retainer from the cylinder head with a
screw driver or similar tool as shown in Fig. 3.
Remove Cam Follower and Push Rod Assembly
7. Unscrew the nut at the outer end of the push rod,
(Cylinder Head Not Removed from Engine)
thus releasing the spring.
8. Pull the push rod, spring, spring seats and cam
A push rod, push rod spring, spring seats and cam
follower out through the top of the cylinder head.
follower may be removed from the top of the cylinder
head by using tool J 3092-01 as shown in Fig. 3.
1972 General Motors Corp.
July, 1972
SEC. 1.2.1 Page 3
