Disassemble Differential
Loosen hex head screws and adjusting screw.
Fasten a hoist and lift off axle housing II.
NOTE: Mark axle housing I and II toward each other for correct installation.
Lift differential assembly out of the axle housing.
Pull off tapered roller bearing from the differential case.
(S) grab sleeve
(S) basic set
(S) pressure piece
Mark differential case halves towards each other for correct installation. Loosen and remove the allen head bolts.
Separate differential case halves and remove released components.
Pull off tapered roller bearing, bevel gear side from differential case half.
(S) grab sleeve
(S) basic set
(S) pressure piece
Press bevel gear from differential case half. Pull roll pins out of the differential case half.
The following steps show one version with installed transfer gear.
Trained personnel can easily identify the different disassembly and reassembly steps (according to the version), carry them out.
Loosen hex head screws.
Screw in adjusting screw (guide bolts), tap loosen and remove cover.
(S) adjusting screws
Unlock the hex nut.
Loosen and remove the hex nut and remove the lock plate.
(S) fixture
Pull spur gear out of the housing.
NOTE: In order to have a better illustration, the transfer gear housing has been separated from the axle housing.
(The following steps can be carried out also in a mounted position).
With a rubber hammer, drive the drive pinion out of the axle housing.
NOTE: Pay attention to the released tapered roller bearing.
Remove spacer and pull off tapered roller bearing from the drive pinion.
(S) grab sleeve
(S) basic set
Drive both bearing outer races of the drive pinion bearing out of the axle housing and remove the spacing washer.
Pull bearing outer race of the differential bearing out of the axle housing and remove the spacing washer.
Assemble Drive Pinion
Determine shim thickness to obtain the correct contact pattern.
For this step, insert measuring cylinder into the bore of axle housing I (differential bearing).
Determine dimension A from plane surface to the middle of measuring cylinder.
For Example: 192.40 mm
(S) measuring cylinder
Measure dimension B from plane surface/housing collar to the contact area for the bearing outer race (shim).
For Example: 47.40 mm
NOTE: The front differential does not have the machined surface to take measurements from. The rear differential is shown.
Determine dimension C (= bearing width).
For Example: 32.00 mm
Read pinion dimension.
For Example: 112 - 0.1 = 111.90 mm
Example:
Insert determined shim.
For Example: 1.10 mm
Pull in bearing outer race, using the special installation tool.
(S) assembly jig
(S) thrust rings
Install second bearing outer race firmly against shoulder.
Install the bearing inner race upon the end of the drive pinion and press it firmly against shoulder.
Determine rolling resistance of the drive pinion bearing:
Install the measuring ring upon the drive pinion collar.
(S) measuring ring
Insert pre-assembled drive pinion and place heated bearing inner race firmly against shoulder.
Guide spur gear over the splines of the drive pinion and place it firmly against shoulder.
Install the washer and tighten hex nut by continuous rotation of the drive pinion, until a rolling resistance of 1 to 2 N·m has been obtained.
Check the rolling resistance.
Loosen and remove the hex nut. Remove the washer and spur gear from drive pinion.
Remove drive pinion again.
Remove measuring ring from drive pinion.
Measure dimension X = thickness of spacer, by means of micrometer (measuring range 0 - 25 mm) - see draft.
For Example: 12.15 mm
Install the determined spacer, for example 12.15 mm, upon the drive pinion collar.
Install drive pinion, place the heated bearing inner race firmly against shoulder and guide spur gear upon the splines of the drive pinion.
Replace washer and tighten the hex nut.
Torque limit 550 N·m
(S) fixture
Check the rolling resistance.
If the required rolling resistance of 1 to 2 N·m has not been obtained, correct with corresponding ring.
Assemble Differential
Heat bevel gear in hot oil and place it against the differential case half I, until full contact is obtained.
NOTE: Pay attention to the location of the bores for the roll pins.
Install roll pins (2 for each bore, displaced for 180°).
Insert thrust washer.
Install side gear.
Position the complete differential spider upon the installed side gear.
NOTE: Pay attention to the location of the thrust washers; noses serration point upward.
Place second side gear upon the spider assembly.
Cover the thrust washer with grease and make it adhere in the second differential case half.
NOTE: Pay attention to the installation position.
Replace differential case half.
NOTE: Pay attention to the marks that were made during disassembly.
Install the perforated discs and install the allen head bolts.
Install the differential assembly into a vise and tighten the allen head bolts.
Torque limit (M 12/12.9) 145 N·m
Heat both tapered roller bearings in oil to a temperature of 135°C (275°F) and install them firmly against their shoulder.
Determine backlash and bearing preload on the differential:
Insert shim (thickness 1.7 mm = value of experience) into the axle housing I and install subsequently bearing outer race firmly against shoulder.
(S) driver
(S) handle
Insert bearing outer race of the differential bearing (bevel gear) into special device.
(S) measuring cover
(S) centering ring
Insert differential assembly into the axle housing I and fix it by means of measuring cover.
Fasten special device by means of hex head screws.
Adjust differential free of axial play, using screwed spindle.
Subsequently secure screwed spindle against rotation by means of locking screws - see arrow.
Fasten a dial indicator at the bevel gear and check backlash.
Nominal value 0.13 - 0.28 mm
If the backlash has not been obtained, correct by means of corresponding shim (see figure 78).
Remove measuring device.
Determine dimension A from flange facing to contact surface/bearing outer race.
For Example: 16.50 mm
Measure dimension B from flange facing axle housing II to contact surface/bearing outer race.
For Example: 14.00 mm
Example:
In order to obtain a bearing rolling moment of 1 to 4 N·m, it is necessary to select a 0.1 mm thicker spacing washer.
Therefore, a spacer washer thickness of 2.60 mm.
Insert determined shim, for example 2.60 mm, and install subsequently bearing outer race into axle housing II.
(S) driver
(S) handle
Lift differential assembly out of the axle housing I, cover some bevel gear teeth with prussian blue or paint, and install the differential again.
Replace axle housing II and fasten it provisionally by means of hex head screws.
Rotate the bevel gear for several times in both directions.
Remove axle housing II again.
Lift out the differential assembly and check contact pattern. See the typical example of correct contact pattern.
If the contact pattern is not correct, a failure has been made during the measurements of the drive pinion.
(Repeat Steps, figure 50 to 53).
If the contact pattern is correct, install stub shaft into the axle housing I (required only if the final drive of axle housing II has not or will not be removed).
Grease O-ring and insert it into the groove of axle housing II.
Replace axle housing II and fasten it by means of hex head screws.
NOTE: Pay attention to the markings on both axle housings and to the installation position of the adjusting screws - see arrow.
Torque limit (M18/10.9) 400 N·m
Loosen hex nut and pull off spur gear.
NOTE: This step is required in order to make the reassembly of transmission possible.