GMC 1976 ZEO 6083 Maintenance Manual page 689

24C- 1 2 ONAN MOTOR GENERATOR
tain the correct clearance. The screw is self-locking
and will stay where it is set. A 9/16" open end
wrench is required to hold the tappet while turning
the adjusting screw.
7 . To adjust valves on the right hand cylinder-
turn engine one complete revolution and again line
up mark on the flywheel and the TC mark on the
gear cover . Then follow adjustment procedure given
for left hand cylinder .
8. Install all parts removed in Step 1. Tighten all
screws securely . Torque manifold bolts to specified
torque .
FLYWHEEL
Removing the flywheel is a relatively simple
process, but the following procedure must be fol-
lowed to avoid damage to the gear case and possible
personal injury .
1 . Turn the flywheel mounting screw outward
about two turns.
WARNING : DO NOT REMOVE . THE SCREW
COMPLETELY SINCE IT ACTS AS A RE-
STRAINER WHEN THE FLYWHEEL SNAPS
LOOSE . IF THE FLYWHEEL IS NOT HELD BY THE
SCREW, THE SPRING ACTION IN THE WHEEL
WILL CAUSE IT TO FLY OFF WITH GREAT
FORCE WHICH CAN CAUSE PERSONAL IN-
JURY .
2. Install a puller bar on the flywheel as shown
in Figure 8.
3 . Turn the puller bar bolts in, alternately, until
the wheel snaps loose on the shaft.
Figure 8-Flywheel Removal
CAUTION : Do not use a screwdriver or simi-
lar tool or pry behind the flywheel against
the gear case. The gear case cover is die-cast
material and will break if undue pressure is
applied in this manner.
4. Unscrew the puller from the flywheel, remove
the flywheel mounting screw and washer and pull the
flywheel off the shaft . Take care not to drop the
wheel. A bent or broken fin will destroy the balance .
Always use a steel key for mounting the flywheel .
FLYWHEEL ALTERNATOR
STATOR
After disconnecting stator terminal wires,
remove the three screws securing stator to gear cover
and pull off.
GEAR COVER (FIGURE 9)
After removing the mounting screws, tap the
gear cover gently with a soft faced hammer to loosen
it .
When installing the gear cover, make sure that
the pin in the gear cover engages the metal lined
(smooth) hole in the governor cup. Turn the gover
nor cup so that the metal lined hole is at the three
o'clock position . The smooth side of the governor
yoke must ride against the governor cup. Turn the
governor arm and shaft clockwise as far as possible
and hold in this position until the gear cover is in-
stalled flush against the crankcase. Be careful not to
damage the gear cover oil seal . Adjust the roll (stop)
pin to protrude to a point 3/4" from the cover's
mounting surface.
GOVERNOR CUP
With the gear cover removed, the governor cup
can be taken off after removing the snap ring from
the camshaft center pin. Catch the flyballs while
sliding the cup off.
Replace with a new part, any flyball which is
grooved or has a flat spot ; the ball spacer if its arms
are worn or otherwise damaged; and the governor
cup if the race surface is grooved or rough. The
governor cup must be a free spinning fit on the cam-
shaft center pin, but without any excessive play .
When installing the governor cup, tilt the engine
so the gear is up, then put the flyballs in place. Install
the cup and snap ring on the center pin.