4-30. REAR AXLE - Continued
Differential Lock Air Shift Unit Repair
Air shift unit removed from truck
Replacement of gasket (4) or O-ring
(5) may be done without removing
air shift unit from truck. Whenever
the air shift unit is disassembled
for repair, all O-rings and piston felt
oilers should be replaced.
Remove capscrews (1), lockwashers (2),
cover (3), and gasket (4) from shift unit
housing (6). Drain housing.
Remove locknuts (10), capscrews (9), top
cover (11), and O-ring (12). Discard
locknuts and O-ring.
During the following procedure the
piston (13) will pop out of the
housing by action of the spring (14)
when nut (15) is removed. Take
precautions to prevent injury to
your hands and face.
(3) Remove locknut (15), flat washer (16), and
piston (13) from push rod (17). Remove
and discard O-rings (18 and 19), and felt
Remove compression spring (14) and
piston stop (21).
Remove clevis pin (7) and push rod (17)
Remove actuating lever and pivot pin assembly (8). Do not disassemble actuating lever.
(7) Inspect housing (6) for damage and defects. Replace complete air shift unit if excessive wear or
damage, including deep scoring of piston bore, is noticed.
Inspect actuating lever and pin (8) for wear and deterioration. Replace both parts if either are defective.
If replacement of actuating lever and pin (8) as well as bushings (22) is required, replace
complete air shift unit.