Automobile Parts User Manual

Servicing the Pinion Cartridge Assembly
Section A
Place a suitable container below the axle drain plug underneath the axle centre housing,
remove the plug and drain the oil. Dispose of the oil safely in accordance with local
bylaws and national regulations.
Remove the setscrews securing the pinion cartridge to the centre housing and lift off the
assembly. The cartridge is located to the centre housing on dowels and will require
carefully prising free using a small pry bar or similar suitable tool. Take care not to
damage or lose the shims fitted between the cartridge and centre housing.
Prevent the flange from turning and undo and remove the self locking nut and flat washer
securing the flange to the pinion. Using a suitable puller or drift remove the flange and
gently drift the pinion shaft out through the cartirdge. Take care to avoid damaging the
gear teeth, splines or threads. Prise the oil seals out of the cartridge, slide the old
collapsed spacer off the shaft and discard the spacer.
Note:
A new spacer should always be fitted.
Inspect the bearings for wear or damage, check the teeth on both the crownwheel and
pinion and make a visual check through the differential of the “wheels”. If the front
bearing race on the shaft needs replacing use a suitable bearing puller to avoid
damaging the pinion shaft. If the outer cones need replacing they can easily be drifted
out of each end of the cartridge.
Important: If new pinion bearings are fitted check the crownwheel/pinion backlash. See
Section F Crownwheel Pinion Set Up.
To re-assemble the cartridge reverse the above procedure fitting a new collapsible
spacer, install the pinion shaft through the innermost bearing cone and fit the rear bearing
over the pinion shaft. Carefully fit the new oil seals and pack with one of the
recommended greases. Refit the flange, coat the inner surface of the flat washer with
silicone sealer and loosely refit the washer and self locking nut.
Prevent the flange from turning and tighten the nut until the spacer begins to collapse and
all the end float between the pinion bearing is taken up but without pre-loading the
bearings.
Slowly continue to tighten the nut, frequently checking the preload, until a preload of 4.5-
6.5Kg (9.9-14.3lbs) for new bearings or 2.2-3.50Kg(4.9-7.7lbs) for used bearings is
obtained. The preload is measued by winding a length of string round the flange and
measuring the load required to turn the flange with a spring balance. Care should be
excercised when tightening the pinion nut otherwise the required preload will quickly be
exceeded.
If the old bearings have been reused coat the mating surface of the pinion cartridge and
centre housing with the recommended sealant and fit the original shimpack. Refit the
cartridge onto the centre case.
If new bearings have been fitted refer to Section F.
Refit the drain plug and tighten. Remove the combined filler/level plug located midway
up the rear of the centre housing and refill the axle with oil. Refit and tighten the level
plug.