DS 19 OPERATION No. DS 330-3 : Overhauling a gearbox. Op. DS 330-3 202
TOOLS
b) Fit the planet gear (47) in the box. Insert a fibre washer, the oil groove towards the planet wheel, and a satellite
wheel (48), a thrust washer (49) (the locking tab in the slot in the box) a spindle.
Determine the thickness of the thrust washer for this satellite so that there is no stiffness when turning the
planet wheel. The longitudinal clearance on the planet wheel is 0.30 mm.
Carry out the same operation for the other satellite wheel.
c) Fit the second planet wheel. Fit the crown wheel. The spindles for the satellite wheels are locked by the set-
screw (81).
Tighten the screws to 47 to 50 ft/lbs (6. 5 to 7 m. kg). Make sure that there is no stiffness when turning the
planet wheel and that the longitudinal clearance on the planet wheel is 0. 30 mm; if not, try another planet
wheel.
d) Dismantle the box. Mark the parts, oil and refit. Tighten the crown wheel fixing screws to 47 to 50 ft/lbs (6.5
to 7 m. kg). Fit an iron locking wire through the holes in the heads of the screws so as to prevent any rotation
in the direction of unscrewing. (Do not fit lockplates).
26 To prepare the differential shafts (see Pl. 54)
a) To rectify the brake discs.
Mount the shaft between centres, the disc at the tailstock end, drive the shaft by means of a lathe carrier or dog.
Rectify the disc face, using a facing tool or better still, a grinding wheel.
If the lathe permits, rectify the other face of the disc, without removing, if not, screw a stud in a hole for
fixing the bibax and reverse the assembly between the lathe centres.
Rectify the other face.
b) To check the disc faces. They should conform to the following conditions
- maximum “run-out” at the greatest diameter; 0.17 mm measured at two points diametrically opposite;
- difference in thickness at any point on the disc; 0.03 mm maximum.
NOTE - 1. Do not reduce the original thickness of the disc by more than 1 mm (0.5 mm on each face), the original
thickness of the disc is 12 ± 0.1 mm.
2. It is preferable to use a disc after rectification, rather than fitting a new disc.
c) To fit the brake discs
Put the oil retaining washer (82) on the shaft, see Pl. 54, for position. Offer up the distance piece (83).
Put the mandrel 1767-T in position (see Pl. 63, fig. 1). Cap the oil sealing washer with the centring bush
and fit the distance piece in a press. Put a block under the disc in order to avoid damage to the dowel pins
on the bibax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mandrel 1767-T
27 To prepare the shaft and bearing assembly (see Pl. 54)
NOTE - The differential shaft and housing is shorter on the right-hand side.
To Next Page
Loading...
