Meritor 18X User manual

Maintenance Manual MM-10127
Single Reduction Differential Carrier
18X
Issue September 2017

2Meritor Differential Carrier 18X
Service Notes
Before You Begin
This publication provides installation and maintenance procedures
for the Single Reduction Differential Carrier 18X produced by
MERITOR VS.
The information contained in this publication was current at the
time of printing and is subject to revision without notice or liability.
You must understand all procedures and instructions before you
begin maintenance and service procedures.
You must follow your company's maintenance and
service guidelines.
You must use special tools, when required, to avoid serious
personal injury and damage to components.
Meritor uses the following notations to alert the user of possible
safety issues and to provide information that will help to prevent
damage to equipment and components.
WARNING
A WARN NG indicates a procedure that you must follow
exactly to avoid serious personal injury.
CAUTION
A CAUT ON indicates a procedure that you must follow
exactly to avoid damaging equipment or components.
Serious personal injury can also occur.
NOTE: A note indicates an operational, procedure or instruction
that is important for proper service. A NOTE can also supply
information that will help to make service quicker and easier.
This symbol indicates that you must tighten fasteners to a
specific torque.
Information contained in this publication was in effect at the time the publication
was approved for printing and is subject to change without notice or liability.
Meritor Commercial Vehicle Systems reserves the right to revise the information
presented to discontinue the production of parts described at any time.
Access nformation on Meritor's Web Site
Additional maintenance and service information for Meritor's
commercial vehicle systems component lineup is also available at
www.meritor.com visiting the “Literature on Demand” page.
All rights reserved.
No part of this publication may be reproduced in any form or by any means or
granted to any third parties without thewritten permission of MERITOR.
MERITOR reserves the right to publish revisions at any time for technical or
commercial purposes. Therefore all material contained in this manual is based on
the latest information available at time of publication approval.
Copyright 2013 by MERITOR VS
Document No. MM-10127
Edition: September 2017

3
Meritor Differential Carrier 18X
Contents
05 Section 1: ntroduction
07 Specification & Data
08 Exploded View
09 Exploded View Parts List
10 Section View
11 Section View Parts List
13 Section 2: Maintenance
14 Differential Removal & Installation
14 Checking the Rear Axle ousing
15 Ring Gear & Pinion Adjustment
16 Shim Pack Calculation
18 Carrier Assembly
22 Calculating the Preload Spacer
27 Differential Bearing Assembly
30 Adjust Differential Bearings Preload
33 Tooth Contact Patterns & ypoid Gear Set
38 Installation & Adjustment of the Diff Lock Sensor Switch
41 Section 3: Hypoid Gear Patterns
42 ypoid Gear Pattern Tables
45 Section 4: Pinion Seal Replacement
46 Disassembly
47 Assembly
51 Section 5: Differential Lock Removal
52 Differential Lock Removal
53 Section 6: Tightening Torque Values
& Lubrication
54 Section view
55 Tightening Torque Table
57 Section 7: Troubleshooting
58 Troubleshooting Chart
pg. 59 Section 8: Service Tools
60 MST4209 CT05 Keying Tool - Spigot Bearing
61 MST4210 CT06 Keying Tool Punch -
Spigot Bearing Pinion
62 MST4216 CT12 Wrench - Adjusting Ring
63 MST4400 CT13 Flange lock tool
64 MST4401 CT14 Seal removal tool
65 MST4410 CT26 Fitting tool - Pinion shaft seal
66 MST4707 CT47 Diff. Bearing Cone R/ Tool
67 MST4708 CT48 Diff Lock Spring Compression Tool
68 MST4709 CT49 Diff. Lock Spring Fitting Tool
69 MST4712 CT52 Diff & Crown Wheel lifting Tool
70 MST4713 Wrench - Adjusting Ring L
71 MST4714 Wrench - Adjusting Ring R
72 MST4904 Inner Pinion Bearing Measuring Tool
73 MST4902 Inner Bearing Cup Tool (Pinion)
74 MST4802 Outer Bearing Cup Tool (Pinion)
75 MST4901 Inner Bearing Cone Tool (Pinion)
76 MST4804 Outer Bearing Cone Tool (Pinion)
77 MST4903 Diff. Bearing Cone L/ Tool
78 MST4905 Axle Shaft Punch Tool
79 MST4807 Inner deflector
80 MST4808 Inner ring
81 Section 9: Appendix
82 Available spacers and combination of calculated
spacers
pg.

4Meritor Differential Carrier 18X
Terms used in this manual
Manufacturer:
MERITOR
Manual:
Maintenance manual no. MM-010127
Device:
Single Reduction Differential Carrier 18X
Technician:
Qualified personnel working on the Single Reduction Differential
Carrier maintenance and servicing.
Maintenance and servicing:
Maintenance and servicing refer to periodical checks and/or
replacement of the Differential Carrier or components. It also
refers to the determining of the cause of a malfunction in order to
restore the initial operating conditions.
Operator:
Any person who will use the Single Reduction Differential Carrier
as part of a more complex device.
Warranty
Warranty applies to the Single Reduction Differential Carrier
installed on vehicles for which it was designed. Warranty is void in
the following cases:
• Improper use of the vehicle on which the Single Reduction
Differential Carrier is installed (usage conditions, overloading etc.)
• Tampering with vehicle components that may affect the Single
Reduction Differential Carrier assembly performance.
• Use of non-original spare parts.
• Improper installation, adjustment, repair or modification.
• Poor or improper maintenance (including consumables other
than those specified).
Further information on warranty conditions may be obtained
directly from the manufacturer or by referring to the Meritor web
site www.meritor.com

5
Meritor Differential Carrier 18X
pg.
1
ntroduction
07 Specification & Data
08 Exploded View
09 Exploded View Parts List
10 Section View
11 Section View Parts List

6Meritor Differential Carrier 18X
1Introduction
General description
The differential unit is of the single-reduction type featuring a
hypoid gear set. The bevel pinion is mounted on two taper roller
bearings and a third straight roller bearing. The bevel pinion
setting relative to the drive gear can be adjusted by varying the
thickness of the shim pack located between the inner pinion
bearing cup and the carrier bearing shoulder. The differential
assembly drive gear welded is supported on two taper roller
bearings and is adjusted for end play through two threaded ring
nut adjusters.

Specifications and data
Hypoid pinion bearings
2 taper roller and 1 straight roller bearing
Differential unit
Final Drive ypoid Gear Ratio (and bevel set teeth)* 2.47 (15/37): 2.64 (14/37): 2.85 (13/37): 3.08 (12/37):
3.36 (11/37): 3.67 (9/33): 3.40 (10/34): 4.11 (9/37):
4.63 (8/37): 5.29 (7/37): 6.17 (6/37)
Pinion to Drive Gear Backlash 0.21 ÷ 0.50 mm
Pinion to Crown Backlash Adjustment Adjusting Rings
Differential Bearing Cap Divergence 0.15 - 0.33 mm
Differential Bearing Cap Divergence Adjustment using the Ring Nut Adjusters
Thickness Range for the Shims fitted between the
Bevel Pinion Bearing Cage & the Differential Carrier 0.10 - 0.15 - 0.35 - 0.50 mm
Drive Gear runout 0.20 max mm
Pinion Bearing Preload 4 - 8 Nm without Pinion Seal
* Verify with the Engineering reference the range of the ratio in current production because sometimes some ratios could be already
released but not currently in production.
7
Meritor Differential Carrier 18X
1Introduction

8Meritor Differential Carrier 18X
1Introduction
Exploded view
Fig. 1.1
No Diff Lock OptionPiston (18) and
Shift Shaft (28)
single component.
26
16
15B
14
24
9a 9
1a
12
10b
13 1g
1b
7
8
2b 5
4
3
6
8
1d
1f 1e
1c
17
18
19
28
22
23
11
28
27
22
29
31
30
21
25
7
1
10a
10
4a
4b
3b
3a
9b
9
2a
2
15A
15
20

9
Meritor Differential Carrier 18X
1Introduction
Exploded view Parts list
1
2
3
4
5
6
7
8
9
10
11
12
Ref. Description
Diff Carrier & Cap Assembly
1a Diff Carrier
1b Bearing Cap R (Disjoint)
1c Bearing Split Cap L
1d Capscrew - Bearing Cap R
1e Capscrew - Bearing Cap L
1f Bearing Cap Washer
1g Locator Pin
Differential Gear Set Assembly
2a Drive Pinion
2b Diff Assembly & Drive Gear - Welded
Diff Bearing L Side
3a Diff Bearing Cup L
3b Diff Bearing Cone L
Diff Bearing R Side
4a Diff Bearing Cup R
4b Diff Bearing Cone R
Adjusting Ring R Side
Adjusting Ring L Side
Lock - Adjusting Ring
Capscrew - M6 x 20
Outer Pinion Bearing
9a Outer Pinion Bearing Cup
9b Outer Pinion Bearing Cone
Inner Pinion Bearing
10a Inner Pinion Bearing Cup
10b Inner Pinion Bearing Cone
Spacer (Variable)
Shim - Inner Pinion Bearing Cup (0.10mm)
Shim - Inner Pinion Bearing Cup (0.15mm)
Shim - Inner Pinion Bearing Cup (0.35mm)
Shim - Inner Pinion Bearing Cup (0.50mm)
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Ref. Description
Spigot Bearing
Pinion Seal
Companion Flange & Deflector Assy
15a - Companion Flange
15b - Deflector
Pinion Nut - M60
Shift Fork
Piston
“O”Ring (40mm diameter)
Shift Shaft Spring
Diff Lock ole Cover
Gasket
ex ead Capscrew - M6 x 20
Identification Plate
Clutch Shift Collar
Lock-Nut - Sensor Switch
Sensor Switch
Shift Shaft
ole-End Plate Cover
Blanking Plug - Sensor Switch ole
Washer Plug

10 Meritor Differential Carrier 18X
1Introduction
Section view
Fig. 1B
2
1
3
5
68
12
17
22
16
14
26
25
9
4
10
11
16
Right
Bearing Cap
Left
Bearing Cap

11
Meritor Differential Carrier 18X
1Introduction
Section view - Parts list
1
2
3
4
5
6
8
9
10
11
12
14
16
17
22
25
26
Ref. Description
Pinion Nut
Input Flange
Deflector
Pinion Seal
Outer Pinion Bearing
Spacer (variable)
Diff Carrier
Shim (variable)
Inner Pinion Bearing
Drive Pinion
Spigot Bearing
Bearing Cap L
Bearing Cap Screw
Bearing Cap R
Differential Gear Set Assembly
Sensor Switch
Locknut - Sensor Switch

12 Meritor Differential Carrier 18X

13
Meritor Differential Carrier 18X
pg.
2
Maintenance
14 Differential Removal & nstallation
14 Checking the Rear Axle Housing
15 Ring Gear & Pinion Adjustment
16 Shim Pack Calculation
18 Carrier Assembly
22 Calculating the Preload Spacer
29 Differential Preload
30 Adjust Differential Bearings Preload
32 Tooth Contact Patterns & Hypoid Gear Set
37 nstallation & Adjustment of the Diff Lock Sensor
Switch

14 Meritor Differential Carrier 18X
2Maintenance
ntroduction
In order to ensure reliable and efficient differential unit operation,
maintenance intervals, use of lubricants and correct procedures
specified by the manufacturer should be strictly observed (refer to
Lubrication Maintenance Manual no.1). For further information
contact the manufacturer’s engineering department or refer to the
Meritor Web site at www.meritor.com
Spare parts
Use original Meritor spare parts only.
Differential removal and installation
NOTE: For detailed information see Meritor Manual no. MM1114
or the vehicle manufacturer manuals.
1. If the vehicle is loaded, unload the rear axle before removing
the differential.
2. Place the vehicle on level ground and chock the front wheels.
3. Rest the rear axle on two suitably strong axle stands.
4. Remove the drain plug from the rear axle bottom end and drain
lubricant.
5. Engage differential lock before air pressure falls below 2.8 bars
6. Remove axle shaft mounting screws and washers.
7. Remove axle shafts.
8. Remove propeller shaft.
9. Disconnect compressed air lines and differential lock sensor
switch coupling.
10.Remove differential carrier to rear axle housing fastening
screws (leave two screws in place to prevent the differential
from falling).
11.Safely support carrier assembly with suitable lifting tool to aid
removal. Remove plastic protective plugs fitted to the
extraction screw holes. Fit extractor screws. Remove final 2
carrier screws to withdraw carrier assembly. Mount the carrier
assembly in a suitable fixture and remove the differential lock
assembly as described in Section 5 Differential Lock
Removal.
Checking rear axle housing
Check rear axle alignment to prevent possible distortion from
causing abnormal stress, noise and pneumatic consumption.
nstallation - Reassembly
1. Clean mounting faces and threads thoroughly. Apply a
continuous bead of sealant DC 7091 to the rear axle mounting
face (Fig.2.1a) Ensure the continuous bead of sealant is applied
around the slots in the mounting face to achieve correct
sealing. DO NOT apply the sealant over the slots (Fig 2.1a).
2. Apply sealant (Loctite 510 or 549) to the complete surface of
the joint gasket (Fig 2.1b.)
NOTE: The carrier to housing assembly must be completed within
15 minutes of applying the sealant to the mating surfaces.
Reverse the removal operation sequence and torque fastening
screws/nuts and drain plug to the specifications detailed in
Section 6 Tightening Torques & Lubrication.
Fig. 2.1
Fig. 2.1b
Continuous bead
of sealant
DC7091
Apply sealant
(Loctite 510 or 549)
to the complete surface
Slot
Sealant

15
Meritor Differential Carrier 18X
2Maintenance
Fig. 2.3
Fig. 2.2
Bearing
Tool
MST4904
CAUTION:
Only original Meritor spare parts should be used.
Use of non-original parts could seriously affect differential
unit performance. Use of non-recommended lubricants will
adversely affect performance and service life.
WARNING:
Waste oil disposal must be carried out in conformity with the
legislation in force.
CAUTION:
Differential carrier removal and handling should be
performed using the specified lifting and carrying
equipment.
CAUTION:
During dismantling/reassembly operations always engage
differential lock to ensure alignment of the splined sections
and prevent shift fork bending and spline damage.
Finally, ensure that:
• There are no leakages from air lines.
• Lubricating oil meets manufacturer’s specifications.
• Differential lock cab warning lamp functions correctly.
Ring Gear & Pinion Adjustment
If a new ring gear and drive pinion are to be installed, the correct
thickness of shim pack required between the inner bearing cup
and the carrier must be determined.
When the correct shims pack has been identified, the bearing
preload on the drive pinion must be adjusted. The preload is
controlled by the thickness of the spacer between the inner and
outer cones of the pinion bearings.
Determining the Pinion nner Bearing Dimension
Before assembling the carrier, measure the complete inner pinion
bearing assembly compressed into a suitable service tool
MST4904, as detailed below. Place the complete bearing into a
suitable service tool and rotate it while tightening the tool
(Fig 2.2).
Tighten the tool until the bearing is completely seated (Fig 2.3).
If the tool is not available press the bearing with 1.000 N or 100 kg
load and take measurement in three points - about 120 degrees.
Measure the internal distance between the service tool plates at
three equally spaced points to determine the total width of the
bearing E(Fig 2.3) (e.g. 58.10). Record dimension Eas it is
required for Shim Pack calculation below.”

Carrier Class Pinion Mounting Dimension (mm) (D)
0 314.00
1 313.98
2 313.96
3 313.94
4 313.92
5 313.90
6 313.88
7 313.86
8 313.84
9 313.82
10 313.80
16 Meritor Differential Carrier 18X
2Maintenance
dentifying the Carrier Class & Pinion Mounting Dimension
Note the carrier class stamped on the carrier housing (See table
below). This may be stamped on the carrier outer casing (Fig 2.4)
or the carrier mounting face. The following table contains the
cross reference detail for carrier class code to the mounting
pinion dimension D(eg. 313.90mm)
NOTE: Dimension Dis essential to calculate the new shim pack
requirements when the original ring gear and shim pack are not
available.
Shim Pack Calculation
Calculate the shims required using the appropriate procedure 1, 2
or 3 below.
1. Calculating the Pinion Shim Pack Value - Original Ring Gear,
Pinion & Shim Pack with NOT AVA LABLE REFERENCE NO.
1.1 The standard theoretical pinion mounting dimension Fis
255mm
1.2 Note the Pinion Cone (P.C.) value Hmarked on the drive
ring gear (Fig. 2.6). This can be either a + value or - value,
(e.g. + 0.10mm)
Fig. 2.4
1.3 Using the values identified for E, D, F & above, calculate the
shim pack requirements using the formula provided below.
Formula: D - (F +/- H) - E = Shim Pack Value
e.g. 313.90 - (255 + 0.1) - 58.10 = 0.70mm
NOTE: Use a shim pack as close as possible to the calculation
value obtained. Shims are available in thicknesses of 0.10, 0.15,
0.35 & 0.50mm.
Fig. 2.5
F
Fig. 2.6.
Fig. 2.6.c
Fig. 2.6b
10 +0.10 1 0/00 B/L 0.32

17
2Maintenance
2. Calculating the Pinion Shim Pack Value.
Original Ring Gear & Pinion and Shim Pack W TH
AVA LABLE REFERENCE NUMBER.
2.1. Measure the thickness of the shim pack removed from the
old pinion/drive gear assembly. Use a micrometer or
gauge and record the reading.
2.2. Read the Pinion Cone (P.C) value marked on the drive ring
gear which is to be replaced (Fig.2.6). If it is a plus (+)
number add it to the value recorded at point 2.1
If it is a minus (-) number, subtract it from the value
recorded at point 2.1.
Record the result of the above calculation.
WARNING:
The value obtained at point 2.2 above will be used to
calculate the thickness of the shim pack required to be fitted
between the NNER pinion bearing cup and the differential
carrier to ensure a correct new final drive assembly. Spare
shims which may be required between the NNER pinion
bearing cup and differential carrier are available in
thicknesses of 0.10, 0.15, 0.35 & 0.50mm
2.3. Read the P.C. marked on the new drive gear (Fig 2.6).
Either add or subtract from the calculated value recorded at
point 2.2 above.
NOTE: Where the P.C. figure on the NEW drive gear is a + value
it must be subtracted from the calculated value at point 2.2.
Where the P.C. figure on the NEW drive gear is a - value it must
be added to the calculated value at point 2.2
Refer to the following examples which cover all the possible
calculation combinations.
NOTE: All values are mm.
Example 1:
Original Shim Pack Thickness 0.76
Hmarked on the OLD DRIVE GEAR (-0.10) -0.10
Resulting Value 0.66
Hmarked on the NEW DRIVE GEAR (-0.12) +0.12
Thickness of new shim pack required 0.78
Example 2
Original Shim Pack Thickness 0.76
Hmarked on the OLD DRIVE GEAR (+0.10) +0.10
Resulting Value 0.86
Hmarked on the NEW DRIVE GEAR (-0.12) +0.12
Thickness of new shim pack required 0.98
Example 3
Original Shim Pack Thickness 0.76
Hmarked on the OLD DRIVE GEAR (+0.10) +0.10
Resulting Value 0.86
Hmarked on the NEW DRIVE GEAR (+0.12) -0.12
Thickness of new shim pack required 0.74
Example 4
Original Shim Pack Thickness 0.76
Hmarked on the OLD DRIVE GEAR (-0.10) -0.10
Resulting Value 0.66
Hmarked on the NEW DRIVE GEAR (+0.12) -0.12
Thickness of new shim pack required 0.54
* Hmarked on the new drive gear = ”O” mm
Fit the shim pack as 2 calculation.
NOTE: Use a shim pack as close as possible to the calculation
value obtained. Shims are available in thicknesses of 0.10, 0.15,
0.35 & 0.50mm.
All final drive sets are stamped with a number indicating only a basic
factory backlash between pinion and drive gear. This backlash value
is shown on the drive gear outer diameter (Fig. 2.6A-2.6B - 2.6C)
If the drive gear is not going to be replaced, we suggest the
established backlash recorded before disassembly be used.
For new gears the new backlash should be initially set at 0.38
mm (.015”). Adjust backlash by moving the gear only. This is done
by backing off one adjusting ring and advancing the opposite ring
the same amount, to ensure bearing preload is maintained.
Fig. 2.7

18 Meritor Differential Carrier 18X
2Maintenance
3. Calculating the Pinion Shim Pack Value.
Original Ring Gear & Pinion with REFERENCE NUMBER
NOT AVA LABLE and Shim Pack with REFERENCE NUMBER
AVA LABLE OR NOT AVA LABLE
If you can’t find the Hnumber or it is unreadable, re-install the
same shim that you measured in Step 1. In case the shim pack
used is not available it is possible to use the average of
Manufacturer’s Adjusted Shim Pack value which is 0,6 mm for
the 18X carrier. Check tooth contact pattern and adjust the shim
pack thickness as necessary to achieve the correct contact
pattern.
Carrier Assembly
If a new ring gear and drive pinion are to be installed,the correct
thickness of shim pack required between the inner bearing cup
and the carrier must be determined. Refer to Section 2, Ring
Gear & Pinion Adjustment. When the necessary calculations
have been completed and the correct shim pack has been
identified continue with the carrier assembly detailed below.
CAUTION:
Do not attempt to assemble the carrier assembly before
establishing the correct shim package requirements.
1. Where applicable, use a suitable press and correct size sleeve,
to install the dust shield (deflector) onto the companion flange
(Fig.2.8).
IMPORTANT:
The spigot bearing has a larger radius on one side. This
larger radius must be positioned facing the head of the
pinion (Fig.2.9). The bearing part number should face
towards the operator.
2. Using a suitable service tool, press the spigot bearing on the
nose of the drive pinion until the bearing is flat against the gear
head (Fig.2.10). Ensure the tool locates correctly on the
bearing, applying force to the inner ring only.
Fig. 2.9
Fig. 2.10
Fig. 2.8

19
Meritor Differential Carrier 18X
2Maintenance
Fig. 2.11
Fig. 2.12
Fig. 2.14
A press force of 6 - 8 tons is required (Fig.2.11).
3. Ball stake the pinion spigot in 10 places equally spaced
(Fig.2.12). The suitable service tool (MST4209) has only five
staking balls present (Fig 2.13).
Mark the pinion to form a datum and the staking tool (CT06) in
two places at a 36 degree interval (Fig 2.14).
Align one of the marks on the staking tool with the datum mark
on the pinion.
Apply a load of 20 ton and form 5 staking points (4 tons per
staking point).
CAUTION:
The indentation diameter must be between 3.40 and 4.10
mm, corresponding to a depth of 0.30 to 0.44 mm under a
load of 4 ton and a ball 10 mm in diameter.
Remove the tool and align the second mark on the tool with the
datum mark on the pinion. Again apply a load of 20 ton to
produce the second set of five staking points.
CAUTION:
When under cutting of the pinion nose is present it may be
necessary to adjust the position of the staking points to
ensure they avoid any undercut; in this case a minimum of
5 staking points are required.
36 Degrees
bevel pinion spigot
MST4209
2.3
Fig. 2.13
bevel
pinion
spigot
ndentation
diameter:
3.40÷4.10
2.3
2.3
0.30÷0.44

20 Meritor Differential Carrier 18X
2Maintenance
Fig. 2.15 Fig. 2.17
Fig. 2.16 Fig. 2.18
4. Apply assembly oil to the pinion shaft (Fig 2.15) and press the
inner cone firmly against the pinion head shoulder using a
suitable tool, which applies pressure only on the bearing inner
cone face (Fig.2.16). Apply a press load of 6 ÷ 8 tons.
(MST4902)
5. Press the outer cup of pinion bearing firmly into its bore in the
carrier. Apply a press load of 6 ÷ 8 tons, using a suitable tool
(MST4802), which is the same size as outer race (Fig.2.17).
Press the bearing until is squarely against the shoulder in the
bottom of its bore (Fig.2.18).
Assembly Oil
MST4902
MST4802
CAUTION:
Cups must be firmly seated in the bore- Check with feeler
gauge (0.02mm) after installation.