TM 5-4310-369-14
(a) Install bearing cup in crankcase.
(b) Install bearing on driven end of crankshaft.
(35) and items 31,34,36, and 37 by removing bolts (32).
(c) Install oil seal (56).
(d) Install free-end bearing on crankshaft.
(e) Install crankshaft in crankcase.
NOTE
NOTE
Do not remove bearing cup unless it is to be
Use caution, do not damage oil seal.
replaced with new bearing set.
(f) Assemble items 31,34,33,45,36,37 (see
Do not remove bearing from crankshaft unless
it is to be replaced with new bearing.
(g) Install crankcase cover assembly on crankcase
with bolts (32). Torque bolts.
(c) Pull crankshaft.
NOTE
NOTE
CHECK FIT, the crankshaft should turn freely
Use caution in removing crankshaft so that oil
in the crankcase.
seal (56, figure 5-5) is not damaged.
If crankshaft is too tight, additional shims (items
Do not remove bearing from crankshaft or the
36 or 37) must be used to adjust fit.
bearing cup from the crankcase unless they are
If crankshaft has end play, shims (items 36 or 37)
to be replaced with a new bearing set.
must be removed to eliminate end play.
(d) Remove oil seal only if it is going to be
replaced with new seal.
(2) Piston-cylinder. Check fit before assembling
b. Cleaning, Inspection and Repair.
pistons to connecting rods. Piston without rings must slide
through the cylinder by their own weight and holding the
skirt of the piston with the two thumbs, there should be no
appreciable side motion at any point of piston travel. Refer
Drycleaning solvent, P-D-680, used to clean parts
to table 6-2 for allowable clearance.
is potentially dangerous to personnel and property.
(3) Wrist Pin-Piston.
Avoid repeated and prolonged skin contact. Do
(a) Low Pressure Piston. Wrist pins (48) and (51)
not use near open flame or excessive heat. Flash
point of solvent is 100F (38C).
bores at ambient temperature. Be sure that a piston pin re-
(1) Clean all parts with cleaning solvent, item 5,
taining ring is at each end of the wrist pins before assembling
App. D, and dry thoroughly.
to cylinders.
(2) Examine cylinder bores for wear, scoring,
(b) High Pressure Piston. Assemble bushing (69)
pitting, cracks or other damage. Replace cylinders that
into piston. Press bushing (68) into upper end of connecting
have damaged bores.
rod. Place connecting rod in piston. Press wrist pin (51) into
(3) Measure the clearance between small end of
piston. Install retaining ring (47) into piston. Install lock-
connecting rod and wrist pin. Also measure the clearance
screws (46) into pistons.
between large end of connecting rod and crankshaft. Refer
to table 6-2 for allowable clearances.
NOTE
Insure lockscrew hole alignment is maintained
scuffing, scoring, etc., and replace parts damaged. If parts
between bushing (69) and piston.
exceed clearance listed in table 6-2, replace them.
(5) Inspect tapered roller bearing for rough, pitted,
or scored surfaces. Replace a defective bearing.
c. Reassembly.
stamped on one side of ring indicates top of ring. Oil rings
(1) Crankshaft-crankcase. Before assembling, the
cannot be installed upside down as either position is
crankshaft must be fitted to the crankcase.
correct.
NOTE
CAUTION
If any bearing part is replaced, the entire
Do not hammer piston assembly into cylinder.
Use finger only to compress rings.
bearing assembly must be replaced.
Before reassembling unit, insure that all
NOTE
reference markings are in place.
Stagger piston ring gaps 120.
5-8
