TM 5-3810-294-34
KEY to fig. 4-6.
Refer to figure 4-6 and disassemble as follows.
I. Bolt (16)
a. Remove camshaft gear nut (15) and retainer
2. Washer (16).
(16) holding the gear on the camshaft.
3. Rear bearing cap
b. Using a gear puller, remove gear (17) from the
4. Intermediate bearing caps (5)
shaft and remove thrust plate (18). Remove key (20).
5. Front bearing cap
c. Camshaft bearing (22, 23, 24, and 25) may be
6. Pins (2)
removed if necessary using an end shaft bushing tool.
7. Rod cap bolt (12)
d. Remove oil slinger (26) and with a suitable puller
8. Cap (6)
remove gear (27) from crankshaft (14).
9. Connecting rod bearing (6)
e. Mark each rod for replacement in the same
10. Rear crankshaft bearing
position.
Note. Using a ridge reamer remove the ridge on
11. Thrust washer (2)
12. Intermediate crankshaft bearing (5)
the cylinder wall at the upper end of the ring travel. This
13. Front crankshaft bearing
prevents damage to the piston ring land during removal
14. Crankshaft
of the pistons.
15. Camshaft gear nut
f. Push rod and piston assembly to the top and lift out
16. Retainer
of the crankcase.
17. Camshaft gear
g. Remove retaining rings (28) and, using a piston
18. Thrust flange
ring expander, remove piston rings (29, 30, and 31), in
19. Capscrew (2)
that order.
20. Key
h. Heat the piston in boiling water or a piston heater,
21. Camshaft
and drive piston pin (32) from piston (33). Remove
22. Front bearing
piston pin bushing (34) from rod (35).
23. Second bearing
i. Using a sleeve puller, remove sleeves (36).
24. Third bearing
4-35. Cleaning
25. Rear bearing
a. Clean all parts in a dry cleaning solvent. Clean
26. Oil slinger
carbon from the piston ring grooves with a broken ring or
27. Gear
a ring groove cleaner.
28. Retaining ring (12)
b. Coat each part with clean engine oil to prevent
29. Compression ring (6)
rusting.
30. Intermediate ring (6)
4-36. Inspection
31. Oil ring (6)
a. Inspect camshaft journal for wear. Compare the
32. Piston pin (6)
dimensions of the camshaft as listed in table 1-4.
33. Piston
Examine bearing surfaces for signs of wear or out of
34. Piston pin bushing (6)
round.
35. Connecting rod (6)
b.
Inspect the camshaft lobes for evidence of
36. Piston sleeve (6)
chipping. Compare lifting areas of the cam lobes with
a. Remove valve mechanism and valve push
camshaft should be replaced.
rods, side cover and gaskets, tappets, oil pan, oil
c. Inspect timing gear for wear or damage. Examine
pump, water pump, and gear cover as discussed
thrust flange for wear. Inspect oil pump drive gear.
previously.
d. Inspect camshaft bearings and determine running
b. Rotate the camshaft gear until capscrews (19)
clearance. Compare dimensions with those shown in
can be removed through the holes in the gear.
c. Remove the camshaft (21) from the crank-
e. Inspect crankshaft bearing for wear and evidence
case.
of uneven bearing support. If such evidence is present,
d. Remove the flywheel and housing as
examine the bearing caps and the crankcase for high
described in paragraph 4-19. Remove cap bolts (1),
spots and burrs.
washers (2), rear bearing cap (3), intermediate
f.
Inspect crankshaft journals and measure the
bearing caps (4), front bearing cap (5), and pins
diameter of each journal using a micrometer. Measure
(6). Remove rod cap bolts (7), caps (8), and
each journal at two points, one at right angles to the
bearings (9). Push piston and connecting rod
other, to show any tendency of out of round. Move the
assemblies to top of sleeve bore.
micrometer over the entire width of the journal.
e. Twist crankshaft out of the crankcase.
Compare dimensions with hose shown in table 1-4.
Remove main bearing halves (10, 12, 13), and
g. Inspect rods, caps, bearing shells, and pin
thrust washer (11) from the crankcase.
h. Aline connecting rods using a connecting rod
4-34. Disassembly
4-11
