Operation and maintenance manual

Section 150-0020
SM 2149 5-02
15
Centre Axle - Differential Drive Head
5. Check security of studs (81) in axle casing (64) and
tighten to a torque of 26 - 28 Nm (19 - 21 lbf ft) if
necessary.
6. Install new oil seal (77) into rear end cap (76). Check
3rd differential shaft (73) for damage in region polished
by oil seal lip.
7. Apply a small bead of Hylomar sealant to the corner
of the bearing recess in rear end cap (76) and axle
casing (64).
8. Install rear end cap (76) against 3rd differential shaft
(73) coupling.
9. Install bearing (78) hard against shoulder on 3rd
differential shaft (73). Secure with lockplate (79) and
shaft nut (80) then bend over lock tabs.
10. Insert 3rd differential shaft (73) into axle casing
and ease into position through clutch dog (63), helical
pinion (31) and inner wheel (15). When 3rd differential
shaft (73) is correctly located, drive it fully home.
11. Install spring washer (75) and nuts (74). Evenly
tighten nuts to a torque of 38 - 43 Nm (28 - 32 lbf ft).
Note: Check for a gap of 0.2 mm (0.008 in) maximum
between rear end cap (76) and axle casing (64).
Bearing (78) must not be pre-loaded.
Setting 3rd Diff Lock Mechanism
1. Loosen locknut (29) then screw out stop screw (28)
from helical gear housing (26). See Fig. 21.
2. Apply pressure to engage diff lock. To check that
lock is engaged, hold front coupling flange (2)
stationary, and try to turn differential shaft (73) at rear
flange. If lock is engaged, both flanges will rotate
together.
3. With operating shaft (42) fully forward, apply
Hylomar to stop screw threads (28) and screw in until it
just touches end of operating shaft (42). Release
pressure on operating cylinder (40) and tighten stop
screw a further half a turn and tighten locknut (29) to 13
- 15 lbf ft (18 - 20 Nm). This will allow approximately
0.020 inch (0.51 mm) clearance for clutch dog faces
(63) when fully engaged.
4. Engage then disengage operating cylinder (40) five
times using air pressure and observe that cylinder
moves smoothly in both directions.
(10) and secure with nuts (131) and washers (130).
Evenly tighten nuts to a torque of 38 - 43 Nm (28 - 32
lbf ft).
Note: Check for a gap of 0.2 mm (0.008 in) maximum
between front end cap (3) and 3rd differential housing
(10). Bearing (6) must not be pre-loaded.
19. Install coupling flange (2) and flange nut (1).
Tighten flange nut (1) to a torque of 1 085 - 1 220 Nm
(800 - 900 lbf ft).
20. Lock flange nut (1) in position by peening raised
collar of flange nut into slot in end face of outer cage
half (12).
Place completed assembly in clean storage place until
required for lifting into axle.
Note: If the period before lifting the assembled unit
into the axle is likely to be more than 4 hours,
thoroughly oil all gears and bearings. If it is to be more
than 12 hours, the oil should be of a protective type,
with anti-rust additive such as Shell 'Ensis 40' and the
unit should be stored in a dust proof and damp proof
container.
INSTALLATION
Numbers in parentheses refer to Fig. 1, unless
otherwise specified.
WARNING
To prevent personal injury and property
damage, be sure wheel blocks, blocking
materials and lifting equipment are properly
secured and of adequate capacity to do the job
safely.
Drive Head Unit and Differential Shaft into
Axle Casing
1. Check studs (85) and renew as necessary. Tighten
to a torque of 89 -100 Nm (66 - 74 lbf ft).
2. Apply a thin coating of Red Hermatite to axle casing
(64) face and install new gasket (86).
3. Using suitable lifting equipment, offer drive head unit
to axle casing (64) ensuring that drive head is in
correct position, with matching marks lined up.
4. Install spring washers (104) and nuts (105) then
tighten to a torque of 230 - 258 Nm (170 - 190 lbf ft).