TM 5-3810-294-34
d. Remove all remaining gasket material from parts.
Key to fig. 13-1.
21.
Exhaust valve (8)
e. Clean all bearings carefully with solvent and allow
1.
Capscrew (8)
22.
Exhaust seat (8)
to dry. Do not use compressed air to dry bearings. Coat all
2.
Lockwasher (8)
23.
Valve guide (8)
bearings and metal parts with oil immediately after drying.
3.
Cover (2)
24.
Intake Valve (8)
f. Clean all oil holes and passages with brass probes.
4.
Gasket (2)
25.
Intake seat (81
5.
Bolt (81
26.
Valve guide (8)
13-8. Inspection
6.
Washer (8)
27.
Oil trough (2)
a. Inspect heads for water leaks or cracks in the
7.
Sleeve bearing (2)
28.
Retaining ring (4)
combustion chamber, exhaust ports or around the valve
8.
Pushrod (16)
29.
Washer (4)
seats. Inspect all machined surfaces for mars, pits, etc.
9.
Head bolt (12)
30.
Spring (4)
b. Check heads for warpage. If more than a 0.003
10.
Head bolt (16)
31.
Rocker arm (4)
inch feeler gage can be inserted under the straight edge,
11.
Washer (28)
32.
Sleeve bearing (8)
planing is necessary. The heads may be planed to a
12.
Cylinder head (2)
33.
Rocker arm bracket
maximum of 0.010 inches. Both heads must be planed if
13.
Gasket (2)
34.
Sleeve bearing (8)
14.
Tappet (16)
35.
Spring (4)
either requires planing. c.
Examine each valve for
15.
Spring lock (32)
36.
Bracket (4)
evidence of burning or warping. Inspect valve springs for
16.
Spring retainer (16)
37.
Rocker arm shaft (4)
proper tension (refer to table 1-4). Any evidence of wear,
17.
Outer spring (16)
38.
Expansion plug (21
cracks, or permanent set requires replacement.
18.
Inner spring (16)
39.
Exhaust tube
d. Inspect valve locks for wear and rotate the rotor
19.
Valve rotor (16)
40.
Lifting attachment (2
caps to assure that they are clean and free to rotate.
20.
Oil seal (16)
e. Check valve guide bore dimensions against values
in table 1-4. Inspect for evidence of water leakage around
a. Remove Capscrew (1), Lockwasher (2), cover(3)
the exhaust valve guides.
and gasket (4).
f. Inspect the valve seat inserts for looseness, burned
b. Remove rocker arm bracket bolt (5) washer (6),
or cracked condition.
and lift rocker arm assembly from head.
g. Inspect rocker arm shaft. Check on a surface plate
c. Remove sleeve bearings (7) and pushrods
for signs of bending and / or wear from rocker arms. If the
Note.
Mark pushrods for installation in identical
shaft is bent or shows excessive wear, it must be replaced.
positionsat reassembly.
h. Inspect valve stem contact pad surface of rocker
d. Remove head bolts (9 and 10), and washer (11).
arm, and resurface if wear is excessive. Do not remove
e. Remove cylinder heads (12) and gaskets (13)
more than 0.010 inch of material when resurfacing rocker
Remove tappets (14).
arm pad.
13-6. Disassembly
i. Inspect rocker arm tension springs for breakage or
Refer to figure 13-1 and disassemble as follows
loss of tension.
a. Compress valve springs and remove locks(15).
j. Inspect rocker arm bushings for proper clearance
Release springs and remove retainers (16)outer springs
to shaft. See table 1-4 for wear limits.
(17), and inner springs (18). Remove valve rotor (19)
k. Re-tap damaged threads in tap holes of head.
and oil seal (20).
l. Replace covers if cracked, bent or distorted.
b. Remove exhaust valves (21), exhaust se (22),
and exhaust valve guides (23).Remove take valves (24),
13-9. Repair and Replacement
intake seats (25), and intake valve guides (26). c.
a. Refer to TM 5-3810-294-34P for repair parts.
Remove oil trough (27), retaining rings (2 rings (29),
b. Measure cylinder head height before resurfacing.
and springs (30).
Refer to table 1-4 for minimum height.
d. Remove rocker arms (31), rocker a brackets
c. Clean all carbon from valve and stems, using a fine
(33), bearing (32 and 34), rings (35), a brackets (36)
wire brush or buffing wheel.
from shafts (37). Remove plugs (- and exhaust tube
d. Refacing of valves and valve seats must be done
(39).
with precision equipment to assure a good fit between
13-7. Cleaning
parts. Refer to table 1-4 for valve face and seat angles.
a. Clean head and crankcase deck thoroughly All
e. If valve stem ends are grooved or scored, they
carbon must be removed from the intake manifold
must be ground to true up. Replace all damaged, worn, or
section, bottom face of the head, and from the valve
unserviceable parts.
ports and guide bores.
b. Flush out water passages to remove any
accumulation of salt, slime, or sludge.
c. Clean all metal parts with dry cleaning solvent
(Federal Specification P-S-661) and dry thoroughly.
13-3
