Ring, Pinion and Bearings
CHECKING DRIVE PINION AND CROWN WHEEL FOR PAIRING NUMBER
Each drive pinion and ring gear belonging to a gear set is marked with a serial number which is written on both parts (arrows).
In addition the basic distance of the gears from one another to be adjusted for the respective gear set is always shown with a + or - prefix on the drive pinion.
The shim thickness required for adjusting the drive pinion is to be calculated. Use the specified data sheet for this purpose.
ASSEMBLING AND ADJUSTING GEAR SET
NOTE:
^ The adjustment dimension "A" is the basic design adjustment of the drive pinion, the basic deviation "a" must be within the permitted tolerance in the plus or minus direction.
^ The basic deviation "a" is the dimension which is written on the end face of the drive pinion.
^ If the adjustment dimension is outside the tolerance, the shim (45) which was installed is to be reground or a new shim of suitable thickness is to be installed.
^ However, it is absolutely essential that a new spacer sleeve is used for the tapered roller bearings.
^ The tapered roller bearings (43, 46) of the drive pinion (47) must be installed with a particular preload. This permanent preload is achieved by compressing the spacer sleeve (44) located between the tapered roller bearing inner race and the drive pinion when tightening the hexagon collared nut (40).
^ If the friction torque is too low when turning the drive pinion, i.e. the preload of the tapered roller bearings is too low, the hexagon collared nut (40) is to be tightened slightly.
^ If the specified friction torque was exceeded, the drive pinion is to be removed again and a new spacer sleeve (44) installed.
^ Under no circumstances may the friction torque be reduced by loosening the hexagon collared nut, as the preload of the tapered roller bearings would be too low.
^ This would result in play in the drive pinion when driving and therefore noise from the rear axle drive.
1. Using a suitable press and tools. press tapered roller bearing inner race (46a) onto drive pinion (47)
2. Press-on sleeve, as shown in the illustration above, for tapered roller bearing inner race
3. Calculate shim (45) for pinion bearing outer race and insert in rear axle housing as follows:
a. Use data sheet, gear set adjustment of rear axle: order no. B20.800.98.113.00C, or equivalent
b. Clamp commercially available dial gauge on gauge stand tool No. 363 589 02 21 00 and mount on measuring plate tool No. 140 589 16 23 00, or equivalents
c. Adjust dial gauge on gauging member tool No. 140 589 14 21 00 (051b) part 01 to "0" with approx. 3 mm preload, thereby adjusting the height of the gauging member B1
d. Mount the tapered roller bearing outer race (46b) on the tapered roller bearing inner race of the drive pinion (47) and attach magnetic plate tool No. 140 589 41 63 00 part 03 (052c), or equivalent
e. Install drive pinion in the measuring plate and measure the height of the drive pinion with tapered roller bearing and magnetic plate.
f. Entering figure 1 in the data sheet.
- Read off the difference between the height of the gauging member "B1" and the height of the drive pinion with magnetic plate "B" and enter in the data sheet under figure 1 (e.g. 1.79 mm).
g. Entering figure 2 in the data sheet.
- Read off the basic difference "a" of the drive pinion (+ or -) and enter in the data sheet under figure 2 (e.g. +006).
h. Calculating interim total in the data sheet.
- Add (+) or subtract (-) values from number 1 and number 2 depending on the prefix (+ or -) of the value on the drive pinion.
i. Install gauging member tool No. 140 589 14 21 00 part 01 (051b), or equivalent, of the measuring device in the rear axle housing.
- Screw on gauging member with attachment piece 140 589 14 21 00 part 02 and hexagon bolt
j. Install the left measuring device race tool No. 140 589 41 63 00 part 01 (052e), or equivalent, from the outside inwards precisely up to the stop in the rear axle housing
k. Install the right measuring device race tool No. 140 5894163 00 pare 02 (052d), or equivalent, from the inside outwards precisely up to the stop in the rear axle housing
l. Install dial gauge tool No. 000 589 38 19 00 (052a) with measuring pin, or equivalent, in the measuring device 126 589 00 21 00 (052), or equivalent
- The measuring pin for the dial gauge is screwed into the adjusting piece (052b)
m. Press adjusting piece (052b) 126 589 00 21 00 part 10 against the measuring device and adjust dial gauge to "0" with 2 mm preload
- Tighten clamping screw securely, checking the "0" position of the dial gauge, and correcting if necessary.
n. Install measuring device from the left bore into the rear axle housing.
- When inserting the measuring device (052) into the rear axle housing, ensure the measuring pin of the dial gauge is not damaged in the bore.
o. Entering figure 3 in the data sheet.
- Measure the difference "A1" between the adjusted gauge dimension and the end face of the gauging member and enter in the data sheet under figure 3 in the positive (+) or negative (-) direction (e.g. -0.01 mm measured and thus negative direction)
NOTE:
^ The specification of the positive (+) or negative (-) direction is related to the direction of rotation of the dial gauge pointer.
^ The direction of rotation, starting from the zero position, opposite to clockwise thus means negative direction and clockwise means positive direction.
p. Calculating thickness of shims "S" in the data sheet.
- Add (+) or subtract (-) the interim total of the values from number 1 and number 2, as well as the value from number 3.
- The value calculated gives the thickness of the shim.
EXAMPLE
1. Measure difference of the height of the
gauging member "B1" and the height of
the drive pinion with magnetic plate "B" = 1.79 mm
2. Read off basic difference "a" on the
drive pinion (plus or minus) = + 0.06 mm
= - 0.00 mm
Interim Total = 1.85 mm
3. Measure difference "A1"between the
adjusted gauge dimension and the
end face of the gauging member
Negative direction = + 0.06 mm
Positive direction = - 0.00 mm
Thickness Of Shim "S" = 1.86 mm
q. Remove measuring device and measuring device races from the rear axle housing.
- Remove gauging member.
r. Install shim with the calculated shim thickness 'S" in the rear axle housing.
CAUTION:
^ Only hardened shims may be used.
^ They are available in various thicknesses (refer to parts supplier)
^ If necessary, grind shim appropriately.
4. Using puller tool No. 140 589 01 43 00, or equivalent, pull pinion shaft tapered roller bearing outer races (43e and 46b) into rear axle housing
CAUTION:
^ Ensure shim (45) is installed
^ Ensure outer races are pulled straight in
5. Install spacer sleeve (44) with bearing washers (48) on both sides on drive pinion
- Always replace spacer sleeve and bearing washers
6. Install drive pinion (47), bearings, seal and joint flange (41) to rear axle housing (50) as follows:
a. Position pinion shaft with bearings into case, then support drive pinion with removal and installation tool No. 140 589 10 43 00, or equivalent
b. Check thrust washer (arrow) of tapered roller bearing inner race for exact seating.
c. Install tapered roller bearing inner race (043d) in rear axle housing.
d. Coat new radial seal ring (42) on the sealing lip with suitable hypoid or universal hypoid fluid and mount on the alignment tool No. 140 589 08 15 00 (034), or equivalent
e. Press in tapered roller bearing inner race (43d) and radial seal ring (42) using puller tool No. 000 589 65 33 00 (035), or equivalent
f. Remove puller from rear axle housing with alignment tool and removal and installation tool.
g. Push joint flange (41) onto drive pinion
- Observe any match markings made at disassembly
- Coat contact surface for radial seal ring with suitable hypoid oil or universal hypoid fluid
7. Install hexagon collared nut to pinion shaft, but do not tighten at this time
8. Adjust friction torque of drive pinion bearing as follows:
a. Mount pin wrench (040) and 41 mm wrench socket (04Oa) on the joint flange (41) and carefully tighten the hexagon collared nut in steps until the specified friction torque of 225-250 Ncm is reached
b. During each tightening step of the the hexagon collared nut, turn the drive pinion several time and ensure by applying light blows to the rear axle housing that the tapered rollers are properly balanced in the track.
c. After each tightening step of the the hexagon collared nut, mount the torque meter (04Ob) with connecting piece (040c) on the 41 mm wrench socket (04Oa) and rotate drive pinion at approx. 60 rpm, reading off the friction torque.
d. If the specified friction torque is exceeded. remove the drive pinion again and install a new spacer sleeve
9. Check adjustment dimension of drive pinion as follows:
b. Mount the magnetic plate part 05 (052c) of measuring race set tool No. 140 589 41 63 00, or equivalent, on the end face of of the drive pinion (47) to measure the adjustment dimension "A"
c. Install the left (052e) part 01 and right (052d) part 02 races of measuring race set from inside outwards precisely up to the stop in the housing
d. Install dial gauge tool No. 000 589 38 19 00 (052a) with measuring pin into the measuring device tool No. 126 589 00 21 00 (052), or equivalents
e. Press the adjusting piece tool No. 126 589 00 21 00 part 10 (052b), or equivalent, against the measuring device and adjust dial gauge to "0" with 2 mm preload
- Tighten clamping screw, while checking the "0" position of dial gauge, reset if necessary
- Measuring pin for dial gauge is screwed into the adjusting piece (052b)
NOTE: When inserting the measuring device (052) in the rear axle housing, ensure the measuring pin of the dial gauge is not damaged in the bore
f. Insert measuring device from the left bore into the rear axle housing
g. Read off adjustment dimension "A"
- Adjustment dimension must be within the tolerance shown on end face of drive pinion
h. Correct as required
i. Remove measuring device and magnetic plate from rear axle housing
10. Using a suitably modified chisel, secure hexagon collared nut (40) on joint flange as shown in the illustration
11. Disassemble and assemble differential (13) as required, refer to Differential Gears and Ring Gear (crown wheel) Carrier
12. Install crown wheel (47a) on differential as follows:
- Observe match marking on crown wheel and differential
a. Carefully clean crown wheel bore and crown wheel seat on the differential housing
b. Heat up crown wheel (47a) to installation temperature of 75-85° C using hot plate (080), constantly checking the temperature with a suitable thermometer (070)
c. Clamp differential housing using assembly mandrel tool No. 116 589 18 61 00 (046), or equivalent
d. Mount crown wheel (47a) on the differential housing, assisting with light blows from a suitable soft hammer if necessary.
- Pay attention to any match marking applied (arrow) on the crown wheel and differential housing.
e. Evenly and diagonally, tighten the locking bolts with ribs (13a) for mounting the crown wheel (47a) securely to: 85 Nm
- Crown wheel bolts (13a) must always be replaced after they have been used once.
13. Using driver tool No. 116 589 08 61 00 (047), or equivalent, press tapered roller bearing inner races (11b) onto differential
- To prevent bearing damage, support assembly using mandrel (046)
14. Install differential by rotating assembly into rear axle housing as shown in the illustration
15. Insert mandrel (046) into differential through case, then press right tapered bearing outer race (11a) in until it abuts inner race (11b)
16. Using circlip pliers (064), insert the right locking ring (29), which was marked during removal, in the slot so that the oil bore (arrow) is not covered.
- Insert the locking ring which was removed and marked previously in order to achieve the basic preload of the rear axle housing.
- Check locking ring (29) for correct seating.
17. Install left tapered roller bearing outer race (11a) in rear axle housing
- The tapered roller bearing outer race must abut the tapered roller bearing inner race
- Do not attempt to install left locking ring at this time
18. Remove both assembly mandrels from differential
19. Preload (expand) rear axle housing using expanding device as follows:
a. Secure expanding device (058) on rear axle housing, by tightening the collared bolts (arrows) securely to 50 Nm.
b. Turn the straight surface (arrow) of the thrust piece downwards.
c. Screw in threaded shaft (058a) by hand, until the thrust piece abuts the tapered roller
d. Place contact arm (059) on expanding device for expanded dimension measurement and press against the two pins from below
- Set dial gauge on "0. with 3 mm preload
- The stop pin (arrow) of the contact arm must abut the bearing surface of the rear axle housing
e. Screw in the threaded shaft (058a) of the expanding device until the rear axle housing has reached the specified expanded dimension of 0.11-0.17 mm
CAUTION: Do not exceed 0.17 mm when expanding center piece
f. Remove contact arm (059)
20. Insert left locking ring (29)
- Install the locking ring which was removed and marked previously in order to achieve the basic preload of the rear axle housing.
21. Release load on rear axle housing
22. Measure expanded dimension (expansion) of rear axle housing again using contact arm (059)
- If the expanded dimension is outside the specified value of: 0.11-0.17 mm, note this value for later adjustment procedures
- Remove contact arm (059).
23. Measure gear backlash between drive pinion and crown wheel and correct if necessary as follows:
a. Install gear backlash measuring device (037) with dial gauge in the right-hand bore of the differential housing and clamp securely.
b. Set dial gauge on "0" with 3 mm preload.
c. Hold the drive pinion securely at the joint flange and press the crown wheel upwards and downwards alternately, reading off the gear backlash.
d. Carry out the measurement four times, always turning the crown wheel through a further 90° each time.
NOTE:
^ The adjustment of the tapered roller bearings and the gear set is in order if the expanded dimension (expansion) of the rear axle housing and the gear backlash are within the range of 0.08-0.14 mm
^ If these values are not achieved, the adjustment must be repeated with suitably thicker or thinner locking rings
e. Remove gear backlash measuring device.
f. If either measurement is incorrect proceed as shown below:
Example 1
Measurement:
Gear backlash correct, but the expanded dimension of the rear axle housing is too small, e.g. measured expanded dimension value is 0.05 mm.
Correction:
Fit a 0.05 mm thick. locking ring on both sides, the gear backlash can change slightly in the process.
Example 2
Measurement:
Expanded dimension correct, but the gear backlash is too large.
Correction:
A locking ring which is thinner by the missing amount is to be installed on the left assembly side.
A locking ring which is thicker by the missing amount is to be installed on the right assembly side (crown wheel side).
Proceed in the reverse order if the gear backlash is too small.
g. The adjustment of the tapered roller bearings and the gear set is in order if the expanded dimension (expansion) of the rear axle housing and the gear backlash is within the range of the specified values
24. Coat outside and sealing lip of drive flange radial seal ring with hypoid or Universal hypoid gear oil, then using drift tool No. 140 589 10 15 00 (032c), or equivalent, press in radial seal ring (32a) into rear axle housing (50)
25. Install connecting flanges (33) into differential (13)
26. Mount new locking rings (30) on connecting flanges
- Replace locking ring
27. Using suitable measuring tool check and adjust axial play between connecting flange (33) and differential side gear (17), if necessary, fit a locking ring (30a) of greater or lesser thickness.
- The axial play must be within: 0.03-0.30 mm
- Locking rings are available in thickness ranging from 1.4 mm to 2.7 mm in 0.05 mm graduations.
28. Clean sealing surface of end cover (54) and coat with Hylomar sealing agent part No. 001 989 25 20, or equivalent
29. Install end cover and collard bolts, then tighten to: 50 Nm
30. Detach rear axle center piece from mounting rack
31. Replace rear axle breather (55) on end cover (54) and tighten to: 30 Nm