Operation and maintenance manual

SM 2149 5-02
Centre Axle - Differential Drive Head
Section 150-0020
8
If torque obtained is greater than 2.8 Nm (25 lbf in) then
a larger outer spacer needs to be fitted.
Note: If largest available combination of spacers
(111 & 112) is already fitted, then a defect must be
present in one or more parts of the assembly and
needs to be found and remedied before continuing
differential build.
4. When correct pre-load has been achieved, remove
end nut (117) and helical gear (116).
5. Apply Loctite 638 by brush to spiral bevel pinion (33)
splines and thread and also end nut (117) clamping
face.
6. Install helical gear (116) and end nut (117). Lock
helical gear (116) using suitable tool.
7. Tighten end nut (117) to a torque of 1085 - 1220 Nm
(800 - 900 lbf ft).
8. Lock end nut (117) in position by peening raised
collar of nut into slot cut in end face of spiral bevel
pinion (33).
Differential Lock Mechanism and 3rd
Differential Driveshaft
1. Using capscrews (41), install air cylinder (40) to
operating shaft (42).
2. Fit clutch dog (63) to operating fork (44) using
retaining spring (43).
3. Hold operating fork assembly in position in gear
casing (39) with clutch dog engagement teeth facing
forward. Install operating shaft (42) through gear casing
(39), operating fork (44) and into the hole in the front of
gear casing.
4. Insert lockpin (101) into operating fork (44) and shaft
(42) through diff lock switch hole in gear casing. Install
washer (102), diff lock switch (103) and plug (38) into
gear casing (39).
Note: Setscrew (28) must be set in the correct position
after the third diff driveshaft is installed. See "Setting
3rd Diff Lock Mechanism".
Differential Unit
1. If crownwheel (46) has been separated from
differential housing body (48) refit as follows:
a. Heat crownwheel (46) to a temperature of
approximately 150° C (300° F). This is necessary to
ensure that crownwheel fits onto register on differential
housing body (48).
b. Place crownwheel (46) into position on differential
housing body (48), ensuring that bolt holes and
matching marks line up.
c. Install two bolts (45) diagonally opposite, through
crownwheel (46) and differential housing body (48)
then allow assembly to cool fully.
d. Install end flange (49) aligning matching marks and
grooves in end face with those in differential housing
body (48). Install remaining bolts (45) and nuts (50) then
tighten to a torque of 155 - 171 Nm (114 - 126 lbf ft).
2. Place assembly on bench with end flange (49)
downwards. Check tightness of studs (47) and if
necessary tighten studs (47) to a torque of
19 - 22 Nm (14 - 16 lbf ft).
3. Soak friction plates (91) in gear oil for at least 30
minutes prior to installing to ensure complete
impregnation. Lightly oil differential components before
assembly.
4. Install first thrust washer (53) into bore of end flange
(49).
5. Slide steel clutch plate (95) then friction plate (91)
into differential housing body (48), making sure that
they are free to move vertically in grooves.
6. Similarly, install second pair of clutch plates
followed by mating cage half (96).
Note: The clutch plates and cage half must be
assembled as the original matched set to ensure
correct operation of POWR LOK system. If unsure as
to which parts complete a set, measure total thickness
of clutch plates and cage half for both sides of
differential unit. Each total thickness figure must be the
same (See Fig. 8).
7. Install wheel (97) into cage half (96) engaging
splines with both friction plates (91) and end face hard
against thrust washer (53).
8. Assemble pinions (99) onto trunnion (98) and lay
assembly in place in cage half (96), in mesh with wheel
(97) as shown in Fig. 9.
9. Add remaining wheel (97) and cage half (96).
10. Stack alternate friction and steel clutch plates