tapered valve lock. Exercise care to avoid scoring
d. Remove Ring Gear From Flywheel.
the valve stem with the valve cap when compressing
(1) Note whether the teeth on the ring gear are
chamfered. The replacement gear must be installed
so the chamfer on the teeth faces the same direction
as on the gear that is to be removed.
If valve guide oil seals are used, compress the valve
(2) Support the flywheel, crankshaft side
spring only enough to permit installation of the valve
down, on a solid flat surface or hardwood block,
locks. Compressing the spring too far may result in
damage to the valve guide oil seal.
which is slightly smaller than the inside diameter of
the ring gear.
(7) Release the tool and install the valve locks
(3) With a suitable drift and hammer, drive
o n the remaining exhaust valves in the same
the ring gear off of the flywheel. Work around the
circumference of the ring gear to avoid bending the
(8) Check the position of the exhaust valve
gear on the flywheel.
e. Install Ring Gear on Flywheel.
(9) Install the injectors, rocker arms, shafts,
(1) Support the flywheel, ring gear side up, on
brackets, and any other parts that were previously
a solid flat surface.
removed from the cylinder head.
(2) Reset the ring gear on a flat metal surface
(10) Install the cylinder head (para 3-19).
and heat the ring gear uniformly with an acetylene
(11) Perform a complete engine tune-up.
torch, keeping the torch moving around the gear to
(12) Start the engine and check for leaks in the
f u e l , water and lubrication system. Install the
rocker arm cover (TM 10-3930-243-12).
Do not, under any circumstances, heat
the gear over 400°F., excessive heating
e. General. The flywheel is attached securely to
m a y destroy the original heat treatment.
the rear end of the crankshaft with six bolts in any
If available, use a heat indicating
one of six positions. A starter ring gear is shrunk
crayon to insure against overheating of
onto the rim of the flywheel.
the ring gear.
b. Removal of Flywheel.
(3) Use a pair of tongs to place the gear on t h e
(1) Remove the engine (para 2-6).
flywheel with the chamfer, if any, facing the same
(2) Remove the shaft and flywheel cover (A,
direction as on the gear just removed.
(4) Tap the gear into place against the
(3) Remove the coupler (B).
shoulder on the flywheel. If the gear cannot be
(4) Remove the flywheel (C).
t a p p e d into place readily, remove it and apply
additional heat, heeding the above caution about
When removing or installing the at-
taching bolts, hold the flywheel firmly
f. Installation of Flywheel.
against the crankshaft by hand to
(1) If a pilot bearing is used in the bore of the
prevent it from slipping off the end of
f l y w h e e l and was removed, install the bearings.
the crankshaft. The flywheel is NOT
Install a new seal ring if one was previously used.
dowelled to the crankshaft.
(2) Mount the flywheel, using lifting tool and
chain hoist, into position against the rear end of the
(1) Inspect flywheel for cracks, scoring or
o v e r h e a t i n g of the clutch contact face. If the
(3) While holding the flywheel in place by
flywheel clutch surface is scored, it may be refaced.
hand, remove the flywheel lifting tool and install
However, not more than 0.020 inch of metal should
t h e flywheel attaching bolts and scuff plates.
be removed from the flywheel and all radii should
Tighten the bolts to 130-140 foot-pounds torque.
be maintained. If the contact face of the clutch
( 4 ) Mount a dial indicator on the flywheel
wear plate shows signs of overheating or excessive
housing or clutch housing and check the runout of
scoring, replace the wear plate.
the flywheel at the clutch contact face. Maximum
(2) Although the flywheel seldom wears to the
a l l o w a b l e runout is 0.001 inch total indicator
point of requiring replacement, the flywheel ring
reading per inch of radius (the radius is measured
g e a r may become worn due to normal usage or
from the center of the flywheel to the outer edge of
damaged by improper use of the starting motor to
the clutch contact face of the flywheel).
t h e extent that it must be replaced. Inspect the
teeth on the ring gear.