TM 9-2320-272-24-4
5-25. CYLINDER HEAD REPAIR (Contd)
b. Cleaning
Clean all cylinder head components (TM 9-247).
c. Inspection
1.
Inspect cylinder head (1) for cracks, pits, and scratches.
a. If pitted or scratched, remove with crocus cloth.
b. If cracked, excessively pitted or scratched, replace cylinder head (1).
2.
Inspect cylinder head (1) for warping.
a. Using straight edge and feeler gauge, inspect gasket surface of cylinder head (1) from front to
rear. Warping should not exceed 0.008 in. (0.20 mm).
b. Inspect gasket surface of cylinder head (1) from side to side. Warping should not exceed 0.003 in.
(0.076 mm).
c. Using 2-in. (51-mm) straight edge and feeler gauge, inspect for warping across valve ports (2) and
coolant passages (5). Warping should not exceed 0.001 in. (0.025 mm).
CAUTION
Machining of cylinder head surface is not to exceed 0.040 in.
(1.02 mm) or damage to equipment will result.
d. Replace or resurface cylinder head (1) if warping exceeds limits. Notify your supervisor.
NOTE
Perform steps 3 and 4 if cylinder head was resurfaced.
3.
Install valves (3) in their respective valve ports (2).
4.
Using gauge block, measure depth of valves (3). Mark valve seat(s) (6) for resurfacing if depth is less
than 0.043 in. (1.09 mm).
5.
Remove valves (3) from cylinder head (1).
6.
Inspect valve springs (4) for distortion, cracks, and collapsed coils. Refer to table 5-9, Cylinder Head
Wear Limits, for measurements. Replace valve springs (4) if damaged or worn.
7.
Using spring tester, compress valve springs (4) to 2 in. (51 mm). Load measured should be
101.2-115 lb (45.9-52.2 kg). Replace valve spring(s) (4) if not within limits.
8.
Inspect valve spring retainers (8) for wear and distortion. Replace valve spring retainer(s) (8) if
worn or distorted.
Table 5-9. Cylinder Head Wear Limits.
WEAR LIMITS/TOLERANCES
ITEM/POINT OF MEASUREMENT
ITEM NO.
INCHES
MILLIMETERS
Intake and exhaust valves
3
1.52
0.060
Rim thickness
9.47
0.373
Valve stem diameter
14
Exhaust valve guide
0.896
22.76
Valve guide length
0.376
9.55
Valve guide bore, inner
15
Intake valve guide
0.893
22.68
Valve guide length
0.376
9.55
Valve guide bore, inner
4
Valve springs
2.585
65.66
Free length
5-160
