Assemble
Prior to re-assembly, coat all plates and discs with Powr-lok oil.
Fig.1b:
Refit two Belleville clutch plates (2, Fig.1b)so that the convex sides are against the differential casings (1 and 8, Fig.1b).
Refit the clutch plates (4, Fig.1b) and clutch discs (3, Fig.1b) as shown into each half of the differential casings (1 and 8, Fig.1b).
Fit the differential side ring (5, Fig.1b).
Position one pinion side gear into the ring recess (4, Fig.1b).
Fit the cross-shafts. Refit the pinion mating cross-shafts complete with pinion gears, ensuring that the ramps on the shafts coincide with the mating ramps in the differential case (7, Fig.1b).
Assemble the remaining pinion side gear (6, Fig.1b) and differential ring (5, Fig.1b).
Offer up the RH half of the differential case (8, Fig.1b) to the flange half in accordance with the identification marks, and position the clutch friction plate tongues so that they align with grooves in the differential case.
Assemble the RH half to the flange half of the differential case using eight bolts (9, Fig.1b), but do not tighten at this stage.
Insert the two output drive shafts into each end of the differential assembly to align the unit.
Fig.2:
Fig.3:
Torque tighten the eight bolts (1, Fig.2; 1, Fig.3) while the drive shafts (2, Fig.3) are in position.
With one drive shaft locked, the torque to turn the other (2, Fig.3) should be 54-94 Nm (40-70 lb/ft).
Remove the two output drive shafts from the differential assembly.
Note: Ensure that prior to assembly, the crown wheel mounting face is free from damage or burrs, particularly on the edge. Should any burrs be left on the carrier they must be removed with an oil stone, prior to fitment of the crown wheel.
Fit the crown wheel to the carrier.
Fit and torque tighten the ten securing bolts and tab washers.
Fig.1c:
Thickness of shims required in the installation of the differential side bearings is determined as follows: Fit the differential side bearings (1, Fig.1c) using Service Tools 18G 134 (2, Fig.1c) and SL550-1 (3, Fig.1c), without the shims, onto the differential case, making sure that the bearings and housing are perfectly clean.
Place the differential assembly, with the bearings in their housing, into the differential case without the pinion in position.
Fig.2c:
Fit a dial indicator gauge to the unit, setting the button against the back face of the crown wheel (Fig.2c).
Inserting two levers between the housing and the bearing cups, move the differential assembly to one side of the carrier.
Set the dial indicator to zero.
Move the assembly to the other side and record the indicator reading, giving the total clearance between bearings (as now assembled) and abutment faces of the gear carrier housing.
Remove the differential assembly from the gear carrier.
Fig.3:
Re-install the pinion outer bearing cup using Service Tools 18G 134 (1, Fig.3c) and SL 550-8 (2, Fig.3c).
Fig.1d:
Fit the inner bearing cup (1, Fig.1d) and shims using tools 18G 134 and SL550-9 (2, Fig.1d).
Fig.2d:
Press the inner bearing cone onto the pinion using tools 18G 47 (1, Fig.2d), SL47-1/1 (2, Fig.2d) and SL 47-1/2 (3, Fig.2d).
Note: The hypoid drive pinion must be correctly adjusted before attempting further assembly, the greatest care must betaken to ensure accuracy.
The correct pinion setting is marked on the ground end of the pinion. The matched assembly serial number is also marked on the periphery of the crown wheel, and care should be taken to keep similarly marked gears and pinions in their matched sets as each pair is lapped together before despatch from the factory.
The letter on the left is a production code letter and has no significance relative to assembly or servicing of any axle. The letter and figure on the right refer to the tolerance on offset or 'pinion drop' dimension, which is stamped on the cover facing of the gear carrier housing.
Fig.3d:
The number at the bottom gives the cone setting distance of the pinion and may be Zero (0), Plus (+) or Minus (-) (Fig.3d).
When correctly adjusted, a pinion marked Zero will be at the zero cone setting distance dimension; which is 66.67 mm (2.625 in.) (i.e. from the centre line of the gear to the face on the small end of the pinion). A pinion marked Plus two (+2) should be adjusted to the nominal (or Zero) cone setting plus 0.0508 mm (0.002 in.), and a pinion marked Minus two (-2) should be adjusted to the cone setting distance minus 0.0508 mm (0.002 in.).
Thus for a pinion marked Minus two (-2), the distance from the centre of the drive gear to the face of the pinion should be 66.619 mm, i.e. 66.67-0,0508 mm (2.623 in., i.e. 2.635-0.002 in.); and for a pinion marked Plus three (+3), the cone setting distance should be 66.746 mm (2.628 in.).
Place the pinion, together with inner bearing cone, into the gear carrier.
Fig.4:
Dimensions Key to Fig.4d:
A Pinion drop 38.1 mm (1.5 in.)
B Zero cone setting 66.67mm (2.625 in.)
C Mounting distance 108.52 mm (4.312 in.)
D Centre line to bearing housing 139.57- 139.83 mm (5.495-5.505 in.).
Turn the carrier over and support the pinion with a suitable block of wood for convenience, before attempting further assembly.
Fit the pinion outer bearing cone, companion flange, washer and nut only, omitting the collapsible spacer, oil thrower and oil seal.
Tighten the nut to remove all backlash.
Fig.1e:
Check the pinion setting distance by means of Service Tool gauge 5L3 (1, Fig.1e).
Adjust the bracket carrying the dial indicator using Service Tool 4HA setting block (2, Fig.1e) and set the dial face to zero.
Check the pinion setting by taking a dial indicator reading on the differential bearing bore with the assembly firmly seated on the ground face of the pinion (3, Fig.1e).
The correct reading will be the minimum obtained; that is, when the indicator spindle is at the bottom of the bore.
Slight movement of the assembly will enable the correct reading to be easily ascertained.
The dial indicator shows the deviation of the pinion setting from the zero cone setting, and it is important to note the direction of any such deviation as well as the magnitude.
If the pinion setting is incorrect, it is necessary to dismantle the pinion assembly and remove the pinion inner bearing cup.
Add or remove shims as required from the pack locating the bearing cup and re-install the shim pack and bearing cup.
Adjusting shims are available in thicknesses of 0.076 mm, 0.127 mm and 0.254 mm (0.003 in., 0.005 in. and 0.010 in.).
Repeat the setting operations until a satisfactory result is obtained.
Extract the pinion shaft from the gear carrier far enough to enable the outer bearing cone to be removed from the pinion.
Fit the collapsible spacer to the pinion, ensuring that it seats firmly on the machined shoulder on the pinion shaft.
Insert the pinion into gear carrier.
Fig.2:
Refit the outer bearing cone and oil thrower. Using Service Tool 18G 1428 (Fig.2e), fit the oil seal.
Lightly grease the spines of the pinion shaft and fit the flange.
Fit a new washer, convex face outermost. Fit, but DO NOT tighten the flange retaining nut.
Begin tightening the flange nut, stopping at frequent intervals to check the torque required to turn the pinion, using the string and spring balance, until the required torque is obtained.
The flange nut may have to be tightened to as much as 175.5 Nm (130 lbf/ft).
Torque required to turn the pinion bearings and oil seal:
Old bearings 2.3 to 2.8 Nm (20 to 25 lbf/in.).
New bearings 3.4 to 4.5 Nm (30 to 40 lbf/in.).
Note the actual figure required to turn the pinion. If the above values are exceeded, a new collapsible spacer must be fitted.
ON NO account must the nut be slackened off and retightened as the collapsed spacer will not then sufficiently clamp the bearing cones.
Place the differential assembly, complete with side bearings but less shims, in to the housing. Ensure that bearings and housing are perfectly clean.
Fig.2:
Using the shim pack previously selected, vary the shim thicknesses between each bearing cup and the carrier face, to achieve a backlash of 0.15-0.25 mm (0.006-0.010 in.) measured at the outer edge of the ring gear (Fig.1f).
Add an additional 0.07 mm (0.003 in.) shim to each pack and carefully note from which side ofthe differential case the pack was removed.
Remove the bearing cups and cones from the differential case using Service Tools SL 14-3/2 and SL 14-3/1.
Fit the appropriate shim pack to the differential case and refit the bearing cone.
Ensure that the matching shim pack and cone are fitted to the same side of the differential housing that they were removed from.
Lower the differential assembly into position, lightly tapping the bearings home with a hide hammer.
Note: Ensure that the gear teeth are led into mesh with those of the pinion.
CAUTION: Careless handling at this stage may result in bruising the gear teeth.
Fig.2f:
When refining the side bearing caps, ensure that the position of the numerals marked on the gear carrier housing face and side bearing cap coincide (1, Fig.2f).
Fit and torque tighten the cap bolts (2, Fig.2f).
Fig.2:
Mount a dial indicator on the gear carrier housing with the button against the back face of the gear (Fig.1f).
Turn the pinion by hand and check the run out on the back face of the gear.
Run out should not exceed 0.13 mm (0.005 in.).
If run out is excessive, strip the assembly and rectify by cleaning the surfaces locating the drive gear.
Any burrs on these surfaces must be removed.
Fig.1g:
Remount the dial indicator on the gear carrier housing,with the button tangentially against one of drive gear teeth (Fig.1g).
Move the drive gear by hand to check the backlash, which should be 0.15-0.25 mm (0.0080.010 in.).
If the backlash is not to specification, transfer the necessary shims from one side of the differential case to the other to obtain the desired setting.
Check the backlash in at least four positions of the drive gear, ensuring that backlash is always greater than 0.15 mm (0.006 in.).
Check that the torque to turn the input flange is 1.1-2.3 Nm (10-20 lbf/in), additional to the torque measured previously to turn the pinion.
Apply silicon sealant to the cover and housing mating faces.
Refit the rear cover. Fit and torque tighten the cover bolts by diagonal selection.
Refit the speed transducer, fit and tighten the two securing setscrews.
Fig.2:
Before fitting the output shaft assemblies, ensure that the four disc flange bolts (3, Fig.2g) are in position, and that a new O-ring (2, Fig.2g) is fitted.
Lightly oil the splines and outside of the bearing with final drive oil, and fit one of the output shaft assemblies.
Fit and torque tighten the securing bolts (1, Fig.2g).
Repeat this procedure for the other output shaft assembly.
Refit the drain plug.
Refit the final drive unit to the rear suspension unit
Replenish the final drive unit with the correct grade of oil as necessary.
SERVICE TOOLS
18G 1205 Flange Holder
18G 134 Adaptor Handle
SL550-1 Outer Pinion Cup Remover
18G 47 Hand Press
SL 74-3/2 Differential Side Bearing Remover
SL 14-3/1 Differential Side Bearing Remover Buffer
5L3 Clock Gauge Tool
4HA Pinion Height Setting Gauge
SL550-9 Pinion Inner Bearing Cup Replacer
SL550-8/1 Pinion Outer Bearing Cup Replacer
SL47-1/1 Pinion Head Bearing Remover
SL47-1/2 Pinion Head Bearing Replacer
18G 1428 Rear Oil Seal Replacer
SL15A Spanner
18G681 CBW 548 Torque Driver
SL47-311 Output Shaft Outer Bearing Remover
SL47-3/2 Output Shaft Outer Bearing Replacer
JD 14 Dummy Shaft
TORQUE FIGURES
Crown wheel gear attachment 136-150.5 Nm
Differential bearing caps 85.5-97.5 Nm
Output shaft bearing housing to unit 81.5-93.5 Nm
Powr-Lok differential case 58.5-67.5 Nm
Rear cover securing setscrews 20.5-27 Nm
OILS / SEALANTS / LUBRICANTS
Differential oil Shell Spirax Super 90
Differential cover Hylosil 102