ARMY TM 9-2815-253-24
AIR FORCE TO 38G1-93-2
MARINE CORPS TM 2815-24/3
Remove pushrod tubes (8, FIGURE 3-28), seals (9), washers (10) and tappets (11) from crankcase.
Remove seals (12) from cylinder head (6). Discard seals (12).
If necessary, remove capscrew (13) and washer (14).
Position head upright on bench and place a suitable block of wood under head of valve (15 or 16).
Do not stand in front of valve springs while compressing them. Failure to follow this warning could
result In personal Injury.
Using standard valve spring compressor tool remove each valve as follows:
Push down on tool until collets (17) can be removed.
Gently release tool. Remove carrier (18), spring (19), seal (20), and plate (21). Discard seal.
Turn cylinder head (6) over and remove valve (15 or 16).
If valves are to be reused, tag them with cylinder number from which they were removed.
Manufacturer recommends that all valves and springs be replaced during a major overhaul.
Insert hex key (allen wrench) into breather tube (23) to support bore of tube. Using pliers, remove breather
3-27.3. Inspect and Measure.
Using appropriate measuring devices, check components listed in TABLE 3-4 for wear. Replace components
that exceed maximum clearance.
Replace the spring if the length is 1.67 in. (42.5 mm) or less.
Check that intake valve seat is sunk 0.037 to 0.05 in. (0.95 to 1.26 mm) and exhaust valve seat is sunk 0.052 to
0.065 in. (1.33 to 1.64 mm) below combustion surface. If not, regrind valve seats. Refer to paragraph 3-27.4.
Check cylinder head clearance as follows:
This procedure is used to determine what size head gasket is required. Start with medium size
Place head gasket onto crankcase. Align holes in gasket with those in crankcase. Rotate engine so
pistons are below cylinder head deck
Using a very small amount of general purpose grease (630AA), place four pieces of solder (SN60WRAP2)
size 0.062 in. (1.58 mm) thick on pistons as shown in FIGURE 3-30. Space solder on outer edge and as
near as possible in line with piston pin. Care must be taken to ensure that solder will be clear of valve
Install cylinder head and torque bolts. Refer to paragraph 3-27.6.
Manually rotate engine through two complete revolutions.
Remove cylinder head and measure the thickness of solder. This should be 0.0276 to 0.0354 in. (0.7 to
0.9 mm) and is obtained by a single gasket under head.