TM-9-2320-272-24-4
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 4 OF 4
JUNE 1998
TM-9-2320-272-24-4 - Page 386 of 836
TM 9-2320-272-24-4
5-57. ADAPTER HOUSING AND FIRST CLUTCH PISTON MAINTENANCE (Contd)
c. Cleaning and Inspection
1.
For general cleaning instructions, refer to para. 2-14.
2.
For general inspection instructions, refer to para. 2-15.
3.
Inspect twenty-six piston return springs (4) for discoloration due to overheating. If discolored,
discard piston return springs (4)
4.
Inspect twenty-six piston return springs (4) for broken coils or coils distorted due to wear. If broken
or distorted, discard piston return springs (4).
NOTE
Perform step 5 if springs pass visual inspection.
5.
Using spring tester, compress each of twenty-six piston return springs (4) to 0.95 in. (24.1 mm) and
check load. If piston return spring (4) does not give the correct load, discard piston return spring (4).
Refer to table 5-16, Spring Data.
Table 5-16. Spring Data.
SPRING
COLOR
Piston return
Solid orange,
spring
yellow stripe
FREE LENGTH
1.28 in.
(32.5 mm)
COMPRESSED LENGTH
0.95 in.
(24.1 mm)
UNDER LOAD
13.6-16.4 lb.
(60.5-72.9 N)
d.
Assembly
NOTE
Ensure seal rings and lips face piston oil pressure side.
Use oil-soluble grease to hold seal rings in place.
1.
Install new outer seal ring (6) and new inner seal ring (7) on first clutch piston (5).
2.
Place first clutch piston (5) in adapter housing (1).
3.
Place twenty-six piston return springs (4) in first clutch piston (5).
4.
Place cupped side of spring retainer (3) over piston return springs (4).
5.
Place compressor tool on spring retainer (3) and arbor press, and compress twenty-six piston return
springs (4).
6.
Install spring retainer (3) with snapring (2).
7.
Remove compressor tool from spring retainer (3).
8.
Install plug (8) in adapter housing (1). Tighten plug (8) 4-8 lb-ft (5-11 N•m).
5-380
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