TM 5-4320-218-15
Note. When removing camshaft and idler
117. Crankshaft and Camshaft Cleaning,
gear, tag each gear to facilitate installation.
Inspection, and Repair
(5) Remove the connecting rods and pis-
a. Crankshaft.
tons (par. 110f).
(1) Wash the removed crankshaft parts
(6) Remove the six capscrews and lock-
with an approved cleaning solvent
washers that secure the main bearing
and dry thoroughly.
plate to the crankcase; pry off the
(2) Inspect the connecting-rod journals on
bearing plate, gaskets, and any in-
the crankshaft for scoring. Hone the
stalled shims.
journals to remove any slight scoring,
Note, Keep the shims together so that the
or replace a defective crankshaft.
same shims will be reinstalled. If any are
(3) Measure the journals. Replace a
damaged, replace them with shims of the same
crankshaft that is worn more than
thickness.
0.002 inch. The diameter of the crank-
(7) Slide the oil slinger (17, fig. 33)
shaft journal should be between 2.123
from the flywheel end of the crank-
and 2.125 inches.
shaft (13), and carefully remove the
(4) Check the main bearing plate and
assembled crankshaft through the
bearing retainer plate for cracks,
rear opening of the crankcase.
breaks, or burs on the mating surfaces.
(8) Remove the crankshaft gear (16) with
File away any burs; replace a cracked
a press plate by pressing the crank-
or broken plate.
shaft through the gear with an arbor
(5) Check the rear oil seal for damage or
press; remove the woodruff key (10 )
indication of wear. Replace a defec-
from the crankshaft.
tive oil seal.
(9) Remove both bearing cones (14), and
(6) Inspect the bearing cones and cups.
remove the cups (15 ) from the crank-
Ordinarily they should be in good
shaft.
condition. Replace any defective bear-
b. Camshaft.
ing assembly.
(1) Lift the valve tappets (10, fig, 32)
(7) Inspect the hardware for bad threads,
up into the valve 3 chambers of the
rust, or damage incurred during re-
cylinder blocks, and secure them with
moval. If the screws have bad
wire to keep them free of camshaft.
threads, replace the screws. Repair
(2) Screw a 5/16-18NC bolt into one of
the mounting holes by running a tap
the camshaft-gear mounting holes in
into them. Replace any other defec-
the front camshaft journal and, pull-
tive hardware.
ing on the bolt, carefully withdraw
(8) Replace the main bearing-plate gas-
the camshaft.
kets.
b. Camshaft.
(3) With a sharp chisel, punch a hole in
the expansion plug (5, fig. 28) in-
(1) Wash the camshaft and tappets with
stalled in the rear camshaft bore in the
an approved cleaning solvent; dry
crankcase. Pry the expansion plug
thoroughly.
out with a screwdriver.
(2) Inspect the camshaft for alinement,
(4) Remove the three cap screws (41)
scoring, and roughness on the cams
and journals. Repair any slight
and the lockwashers (42) that secure
each splash plate (43 ) to the interior
roughness, or replace a badly scored
of the crankcase.
camshaft.
(5) Release the valve tappets, and remove
(3) Measure the camshaft journals and
them from the bottom of the crank-
cams; replace the camshaft if either
case. Identify each tappet to facili-
the journals or cams are worn beyond
tate installation.
the limits of allowable wear. The No.
