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 32 of 991
TM 9-2320-272-24-2
3-223. FRONT HUB AND DRUM (M939/A1) MAINTENANCE (Contd)
WARNING
Drycleaning solvent is flammable and toxic. Do not use near open
flame and always have a fire extinguisher nearby when solvents
are used. Use only in well-ventilated places, wear protective
clothing, and dispose of cleaning rags in approved container.
Failure to do this may result in injury or death to personnel and/or
damage to equipment.
1.
Clean gasket or sealant remains from mating surfaces of driveshaft flange (14) and hub (2).
NOTE
Do not use compressed air to dry bearings.
2.
Clean all hub (2) and drum (1) components in drycleaning solvent.
3.
Inspect hub (2) for cracks and breaks. Replace hub (2) if cracked or broken.
4.
Inspect inner and outer bearings (4) and (7) (TM 9-214). Replace if damaged.
5.
Inspect inner and outer bearing cups (5) and (6) (TM 9-214). Replace if damaged.
NOTE
Perform steps 6 and 7 only if bearing cups are to be replaced.
6.
Remove bearing cups (5) and (6) from hub (2) by tapping alternately on outer edge.
7.
Press new inner bearing cup (5) and outer bearing cup (6) into hub (2). Ensure bearing cups (5) and (6)
are seated.
8.
Inspect drum (1) for deep grooves. Replace drum (1) if grooves are deeper than l/32 in. (0.79 mm).
1.
Pack inner and outer bearings (4) and (7) with GAA grease (TM 9-214).
2.
Pack inner rubber section of new inner oil seal (3) with GAA grease (TM 9-214).
1.
2.
3.
4.
5.
6.
7.
8.
9.
Install hub (2) in drum (1).
Press wheel studs (8) through drum (1) and into hub (2). Ensure studs (8) are seated.
Install inner bearing (4) and inner bearing oil seal (3) into hub (2). Ensure inner oil bearing oil
seal (3) is seated.
NOTE
Assistant will help with step 4.
Install hub (2) and drum (1) on spindle (9).
Install outer bearing (7) on spindle (9) with nut (10). While rotating hub (2), tighten nut (10) to
50 lb-ft (68 N-m).
Back out nut (10) l/6-l/4 turn so washer (12) can be positioned to spindle (9) and adjusting
pin (11).
Install washer (12) and locknut (13) on spindle (9). Tighten locknut (13) 250-400 lb-ft (339-542 N•m).
Apply sealant to mating surfaces of driveshaft flange (14).
Install new gasket (17) and driveshaft flange (14) on hub (2) with ten new lockwashers (16) and
screws (15). Tighten screws (15) 60-100 lb-ft (81-136 N•m).
3-640
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