TM-9-2320-272-24-2
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 2 OF 4
JUNE 1998
TM-9-2320-272-24-2 - Page 818 of 991
TM 9-2320-272-24-2
4-17. CRANKSHAFT REAR COVER AND SEAL REPLACEMENT
THIS TASK COVERS:
a. Removal
b. Installation
INITIAL SETUP:
APPLICABLE MODELS
REFERENCES (TM)
M939/A1
TM 9-2320-272-24P
TOOLS
EQUIPMENT CONDITION
General mechanic’s tool kit (Appendix E, Item 1)
Flywheel housing removed (para. 4-16).
MATERIALS/PARTS
Rear cover plate gasket (Appendix D, Item 526)
Rear cover plate seal (Appendix D, Item 527)
O-ring (Appendix D, Item 439)
Fourteen screw-assembled lockwashers
(Appendix D, Item 588)
1.
Remove four screw-assembled lockwashers (2) from oil pan (1). Discard screw-assembled
lockwashers (2).
2.
Remove ten screw-assembled lockwashers (4), O-ring retainer (7), retainer gasket (6), cover seal (5),
cover plate (3), and cover plate gasket (9). Discard seal (5), O-ring retainer gasket (6), and plate
gasket (9).
3.
Remove O-ring (8) from O-ring retainer (7). Discard O-ring (8).
b. Installation
1.
2.
3.
4.
5.
6.
7.
8.
Install new cover plate gasket (9) and cover plate (3) on cylinder block (10) with four new screw-
assembled lockwashers (4). Do not tighten.
Install O-ring retainer (7) and gasket (6) over end of crankshaft (11) with six new screw-assembled
lockwashers (4). Do not tighten.
NOTE
Perform steps 3 and 4 to check cover plate runout.
Position dial indicator on end of crankshaft (11) and indicator arm (12) to outside edge of O-ring
retainer (7).
Rotate crankshaft (11) and read dial indicator to align cover plate (3). Cover plate (3) must be
aligned within 0.005 in. (0.127 mm).
Tighten ten screw-assembled lockwashers (4) 24-29 lb-ft (33-39 N-m).
Install new rear cover seal (5) into rear cover plate (3) over rear end of crankshaft (11).
Install new O-ring (8) over O-ring retainer (7).
Install four screw-assembled lockwashers (2) in oil pan (1). Alternately tighten screw-assembled
lockwashers (2) 15-20 lb-ft (20-27N•m).
4-136
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