AxleTech PRC 416-P User manual

• PRC 416-P
• PRC 756-P
Planetary Axle Wheel Ends
Maintenance Manual 9F
Issued 05-98
$2.50

Service Notes
How to Order
Order items from AxleTech International.
Phone orders are also accepted by calling
AxleTech International’s Customer Service Center
at 877-547-3907 or send a fax to 866-547-3987.
WARNING A WARNING indicates a
procedure that you must
follow exactly to avoid
serious personal injury.
CAUTION A CAUTION indicates a
procedure that you must
follow exactly to avoid
damaging equipment or
components. Serious per-
sonal injury can also
occur.
This symbol indicates that
fasteners must be tight-
ened to a specific torque.
NOTE: A NOTE indicates an oper-
ation, procedure or
instruction that is impor-
tant for proper service. A
NOTE can also supply
information that will help
to make service quicker
and easier.
!
!
This maintenance manual describes the correct
service and repair procedures for AxleTech
planetary drive axles, PRC 416-P and PRC 756-P.
The information contained in this manual was
current at time of printing and is subject to
change without notice or liability.
You must follow your company procedures when
you service or repair equipment or components.
You must understand all procedures and instruc-
tions before you begin to work on a unit. Some
procedures require the use of special tools for
safe and correct service. Failure to use special
tools when required can cause serious personal
injury to service personnel, as well as damage
equipment and components.
The instructions contained in this Field
Maintenance Manual are intended for use by
skilled and experienced mechanics knowledge-
able in the installation, repair and replacement of
the AxleTech product described herein.
Installation, maintenance and replacement of
such products require a high degree of skill and
experience. The consequences of improper instal-
lation, maintenance or replacement (including the
use of inferior or substandard components) are
grave and can result in product failure and result-
ing loss of control of the vehicle, possible injury
to or death of persons and/or possible future or
additional axle damage. AxleTech does not autho-
rize anyone other than highly skilled and experi-
enced individuals to attempt to utilize the instruc-
tions contained in this Manual for the installation,
maintenance or replacement of the product
described herein, and AxleTech shall have no lia-
bility of any kind for damages arising out of (or in
connection with) any other use of the information
contained in this Manual.
AxleTech International uses the following nota-
tions to warn the user of possible safety problems
and to provide information that will prevent dam-
age to equipment and components.

Table of Contents
Asbestos and Non-Asbestos Fibers Warning......................................................................................1
Exploded View – PRC 416-P........................................................................................................................2
Exploded View – PRC 756-P........................................................................................................................3
Section 1: Introduction
Description ....................................................................................................................................................4
Identification ..................................................................................................................................................5
Section 2: Removal and Disassembly – PRC 416-P Planetary Axle
Remove and Disassemble the PRC 416-P Planetary Axle Wheel End ......................................................6
PRC 416-P Wheel End Cross Section ........................................................................................................6
Remove the Brake Drum............................................................................................................................6
Remove the Planetary Spider Assembly..................................................................................................8
Disassemble the Brake..................................................................................................................................9
Remove the Spindle and Brake Spider ....................................................................................................9
Section 3: Removal and Disassembly – PRC 756-P Planetary Axle
Remove and Disassemble the PRC 756-P Axle Wheel End......................................................................10
PRC 756-P Wheel End Cross Section ......................................................................................................10
Remove the Brake Drum..........................................................................................................................10
Remove the Planetary Spider Assembly................................................................................................12
Disassemble the Brake................................................................................................................................13
Remove the Spindle and Brake Spider ..................................................................................................13
Section 4: Prepare Parts for Assembly
Clean Ground or Polished Parts ................................................................................................................14
Clean Parts with Rough Finish ..................................................................................................................14
Clean Axle Assemblies................................................................................................................................14
Dry Cleaned Parts........................................................................................................................................14
Prevent Corrosion........................................................................................................................................14
Inspect Parts ................................................................................................................................................15
Inspect Tapered Roller Bearings ............................................................................................................15
Inspect the Bevel Pinion and Ring Gear Sets ........................................................................................16
Inspect the Main Differential Assembly..................................................................................................17
Inspect the Axle Shafts ............................................................................................................................17
Inspect the Yoke ......................................................................................................................................17
Inspect the Brakes ....................................................................................................................................17
Repair or Replace Parts ..............................................................................................................................17
Repair Welding ............................................................................................................................................17
Apply Silicone Gasket Material ..................................................................................................................18
Section 5: Assembly and Installation – PRC 416-P Planetary Axle
Assemble and Install the PRC 416-P Planetary Axle Wheel End ............................................................19
Prepare Parts for Assembly........................................................................................................................19
Assemble the Spindle, Brake Spider and Brake ......................................................................................19
Assemble the Wheel End............................................................................................................................20
Adjust the Wheel Bearing Preload ............................................................................................................21
Assemble the Planetary Spider and Gearing Assembly ..........................................................................21
Install the Planetary Spider Assembly ......................................................................................................22
Section 6: Assembly and Installation – PRC 756-P Planetary Axle
Assemble and Install the PRC 756-P Planetary Axle Wheel End ............................................................23
Prepare Parts for Assembly........................................................................................................................23
Assemble the Spindle, Brake Spider and Brake ......................................................................................23
Assemble the Wheel End............................................................................................................................24
Adjust the Wheel Bearing Preload ............................................................................................................25
Assemble the Planetary Spider and Gearing Assembly ..........................................................................26
Install the Planetary Spider Assembly ......................................................................................................26
Section 7: Specifications
Torque Chart................................................................................................................................................28
Lubrication Specifications ..........................................................................................................................30
Lubrication Schedule ..................................................................................................................................30

Notes

NON-ASBESTOS FIBERS WARNING
The following procedures for servicing brakes are recommended to reduce
exposure to non-asbestos fiber dust, a potential cancer and lung disease
hazard. Material Safety Data Sheets are available from AxleTech.
Hazard Summary
Most recently manufactured brake linings do not contain asbestos fibers. These brake
linings may contain one or more of a variety of ingredients, including glass fibers, mineral
wool, aramid fibers, ceramic fibers and silica that can present health risks if inhaled.
Scientists disagree on the extent of the risks from exposure to these substances.
Nonetheless, exposure to silica dust can cause silicosis, a non-cancerous lung disease.
Silicosis gradually reduces lung capacity and efficiency and can result in serious
breathing difficulty. Some medical experts believe other types of non-asbestos fibers,
when inhaled, can cause similar diseases of the lung. In addition, silica dust and ceramic
fiber dust are known to the State of California to cause lung cancer. U.S. and
international agencies have also determined that dust from mineral wool, ceramic fibers
and silica are potential causes of cancer.
Accordingly, workers must use caution to avoid creating and breathing dust when
servicing brakes. Specific recommended work practices for reducing exposure to non-
asbestos dust follow. Consult your employer for more details.
Recommended Work Practices
1. Separate Work Areas. Whenever feasible, service brakes in a separate area away
from other operations to reduce risks to unprotected persons.
2. Respiratory Protection. OSHA has set a maximum allowable level of exposure for silica
of 0.1 mg/m3as an 8-hour time-weighted average. Some manufacturers of non-asbestos
brake linings recommend that exposures to other ingredients found in non-asbestos
brake linings be kept below 1.0 f/cc as an 8-hour time-weighted average. Scientists
disagree, however, to what extent adherence to these maximum allowable exposure
levels will eliminate the risk of disease that can result from inhaling non-asbestos dust.
Therefore, wear respiratory protection at all times during brake servicing, beginning with
the removal of the wheels. Wear a respirator equipped with a high-efficiency (HEPA)
filter approved by NIOSH or MSHA, if the exposures levels may exceed OSHA or
manufacturer’s recommended maximum levels. Even when exposures are expected to
be within the maximum allowable levels, wearing such a respirator at all times during
brake servicing will help minimize exposure.
3. Procedures for Servicing Brakes.
a) Enclose the brake assembly within a negative pressure enclosure. The enclosure
should be equipped with a HEPA vacuum and worker arm sleeves. With the
enclosure in place, use the HEPA vacuum to loosen and vacuum residue from the
brake parts.
b) As an alternative procedure, use a catch basin with water and a biodegradable, non-
phosphate, water-based detergent to wash the brake drum or rotor and other brake
parts. The solution should be applied with low pressure to prevent dust from becoming
airborne. Allow the solution to flow between the brake drum and the brake support or
the brake rotor and caliper. The wheel hub and brake assembly components should be
thoroughly wetted to suppress dust before the brake shoes or brake pads are
removed. Wipe the brake parts clean with a cloth.
c) If an enclosed vacuum system or brake washing equipment is not available, carefully
clean the brake parts in the open air. Wet the parts with a solution applied with a
pump-spray bottle that creates a fine mist. Use a solution containing water, and, if
available, a biodegradable, non-phosphate, water-based detergent. The wheel hub
and brake assembly components should be thoroughly wetted to suppress dust before
the brake shoes or brake pads are removed. Wipe the brake parts clean with a cloth.
d) Wear a respirator equipped with a HEPA filter approved by NIOSH of MSHA when
grinding or machining brake linings. In addition, do such work in an area with a local
exhaust ventilation system equipped with a HEPA filter.
e) NEVER use compressed air by itself, dry brushing, or a vacuum not equipped with a
HEPA filter when cleaning brake parts or assemblies. NEVER use carcinogenic
solvents, flammable solvents, or solvents that can damage brake components as
wetting agents.
4. Cleaning Work Areas. Clean work areas with a vacuum equipped with a HEPA filter
or by wet wiping. NEVER use compressed air or dry sweeping to clean work areas.
When you empty vacuum cleaners and handle used rags, wear a respirator equipped
with a HEPA filter approved by NIOSH or MSHA, if the exposure levels may exceed
OSHA or manufacturers’ recommended maximum levels. When you replace a HEPA
filter, wet the filter with a fine mist of water and dispose of the used filter with care.
5. Worker Clean-Up. After servicing brakes, wash your hands before you eat, drink or
smoke. Shower after work. Do not wear work clothes home. Use a vacuum equipped
with a HEPA filter to vacuum work clothes after they are worn. Launder them separately.
Do not shake or use compressed air to remove dust from work clothes.
6. Waste Disposal. Dispose of discarded linings, used rags, cloths and HEPA filters with
care, such as in sealed plastic bags. Consult applicable EPA, state and local regulations
on waste disposal.
Regulatory Guidance
References to OSHA, NIOSH, MSHA, and EPA, which are regulatory agencies in the
United States, are made to provide further guidance to employers and workers employed
within the United States. Employers and workers employed outside of the United States
should consult the regulations that apply to them for further guidance.
!
ASBESTOS FIBER WARNING
The following procedures for servicing brakes are recommended to reduce
exposure to asbestos fiber dust, a cancer and lung disease hazard. Material
Safety Data Sheets are available from AxleTech.
Hazard Summary
Because some brake linings contain asbestos, workers who service brakes must
understand the potential hazards of asbestos and precautions for reducing risks. Exposure
to airborne asbestos dust can cause serious and possibly fatal diseases, including
asbestosis (a chronic lung disease) and cancer, principally lung cancer and mesothelioma
(a cancer of the lining of the chest or abdominal cavities). Some studies show that the risk
of lung cancer among persons who smoke and who are exposed to asbestos is much
greater than the risk for non-smokers. Symptoms of these diseases may not become
apparent for 15, 20 or more years after the first exposure to asbestos.
Accordingly, workers must use caution to avoid creating and breathing dust when
servicing brakes. Specific recommended work practices for reducing exposure to
asbestos dust follow. Consult your employer for more details.
Recommended Work Practices
1. Separate Work Areas. Whenever feasible, service brakes in a separate area away
from other operations to reduce risks to unprotected persons. OSHA has set a maximum
allowable level of exposure for asbestos of 0.1 f/cc as an 8-hour time-weighted average
and 1.0 f/cc averaged over a 30-minute period. Scientists disagree, however, to what
extent adherence to the maximum allowable exposure levels will eliminate the risk of
disease that can result from inhaling asbestos dust. OSHA requires that the following sign
be posted at the entrance to areas where exposures exceed either of the maximum
allowable levels:
DANGER: ASBESTOS
CANCER AND LUNG DISEASE HAZARD
AUTHORIZED PERSONNEL ONLY
RESPIRATORS AND PROTECTIVE CLOTHING
ARE REQUIRED IN THIS AREA
2. Respiratory Protection. Wear a respirator equipped with a high-efficiency (HEPA) filter
approved by NIOSH or MSHA for use with asbestos at all times when servicing brakes,
beginning with the removal of the wheels.
3. Procedures for Servicing Brakes.
a) Enclose the brake assembly within a negative pressure enclosure. The enclosure
should be equipped with a HEPA vacuum and worker arm sleeves. With the enclosure
in place, use the HEPA vacuum to loosen and vacuum residue from the brake parts.
b) As an alternative procedure, use a catch basin with water and a biodegradable, non-
phosphate, water-based detergent to wash the brake drum or rotor and other brake
parts. The solution should be applied with low pressure to prevent dust from becoming
airborne. Allow the solution to flow between the brake drum and the brake support or
the brake rotor and caliper. The wheel hub and brake assembly components should be
thoroughly wetted to suppress dust before the brake shoes or brake pads are removed.
Wipe the brake parts clean with a cloth.
c) If an enclosed vacuum system or brake washing equipment is not available, employers
may adopt their own written procedures for servicing brakes, provided that the
exposure levels associated with the employer’s procedures do not exceed the levels
associated with the enclosed vacuum system or brake washing equipment. Consult
OSHA regulations for more details.
d) Wear a respirator equipped with a HEPA filter approved
by NIOSH or MSHA for use with asbestos when grinding or machining brake linings. In
addition, do such work in an area with a local exhaust ventilation system equipped
with a HEPA filter.
e) NEVER use compressed air by itself, dry brushing, or a vacuum not equipped with a
HEPA filter when cleaning brake parts or assemblies. NEVER use carcinogenic
solvents, flammable solvents, or solvents that can damage brake components as
wetting agents.
4. Cleaning Work Areas. Clean work areas with a vacuum equipped with a HEPA filter or
by wet wiping. NEVER use compressed air or dry sweeping to clean work areas. When you
empty vacuum cleaners and handle used rags, wear a respirator equipped with a HEPA
filter approved by NIOSH or MSHA for use with asbestos. When you replace a HEPA filter,
wet the filter with a fine mist of water and dispose of the used filter with care.
5. Worker Clean-Up. After servicing brakes, wash your hands before you eat, drink or
smoke. Shower after work. Do not wear work clothes home. Use a vacuum equipped with
a HEPA filter to vacuum work clothes after they are worn. Launder them separately. Do not
shake or use compressed air to remove dust from work clothes.
6. Waste Disposal. Dispose of discarded linings, used rags, cloths and HEPA filters with
care, such as in sealed plastic bags. Consult applicable EPA, state and local regulations on
waste disposal.
Regulatory Guidance
References to OSHA, NIOSH, MSHA, and EPA, which are regulatory agencies in the United
States, are made to provide further guidance to employers and workers employed within
the United States. Employers and workers employed outside of the United States should
consult the regulations that apply to them for further guidance.
!
Page 1
Asbestos and Non-Asbestos Fibers

Page 2
Section 1
Introduction
ITEM DESCRIPTION QTY ITEM DESCRIPTION QTY ITEM DESCRIPTION QTY
1 Brake Drum 1
2 Magnetic Fill/Drain Plug 1
3 Planetary Spider Assembly 1
4 Set Screw 3
5 Machine Screw 5
6 Thrust Button 1
7 Pinion Shaft Assembly 3
8 Outer Thrust Washer 3
9 Planetary Pinion 3
10 Inner Thrust Washer 3
11 Snap Ring 3
12 Snap Ring 1
13 Planetary Sun Gear 1
14 Thrust Washer 1
15 Planetary Ring Gear 1
16 Adjusting Nut Dowel Pin 1
17 Adjusting Nut Assembly 1
18 Outer Bearing Cone 1
19 Outer Bearing Cup 1
20 O-Ring 1
21 Wheel Nut 10
22 Wheel Stud 10
23 Hub and Cup Assembly 1
24 Inner Bearing Cup 1
25 Inner Bearing Cone 1
26 Oil Seal Assembly 1
27 Cap Screw (3/4-10 x 2.75) 13
28 Washer 13
29 Spindle Assembly 1
30 Axle Shaft (Left-Hand, 2
Right-Hand)
PRC 416-P
1
2
3
4
5
6
7
8
9
10
11
12 13
14
15
16
17
18
19
20
23
21
22
24
25
26
27 28
29
30

Page 3
Section 1
Introduction
ITEM DESCRIPTION QTY ITEM DESCRIPTION QTY ITEM DESCRIPTION QTY
1 Brake Drum 1
2 Magnetic Fill/Drain Plug 1
3 Planetary Assembly Cover 1
4 Capscrew 6
5 Hardened Washer 6
6 Thrust Button 1
7 Dowel 3
8 Planetary Spider Assembly 1
9 Machine Screw 5
10 Planetary Pinion Shaft 3
11 Planetary Pinion 3
12 Thrust Washer 3
13 Snap Ring 1
14 Planetary Sun Gear 1
15 Thrust Washer 1
16 Wheel Bearing Nut 1
17 Planetary Ring Gear 1
18 Capscrew 2
19 Lock 1
20 Planetary Ring Gear Hub 1
21 Outer Bearing Cone 1
22 Outer Bearing Cup 1
23 O-Ring 1
24 Hub and Cup Assembly 1
25 Wheel Nut 10
26 Wheel Stud 10
27 Inner Bearing Cup 1
28 Inner Bearing Cone 1
29 Oil Seal Assembly 1
30 Spindle Assembly 1
31 Capscrew 13
32 Hardened Washer 13
33 Axle Shaft (Left-Hand, 2
Right-Hand)
PRC 756-P
12
36
4
5
7
9
8
10
11
12
13
14 15
16
17
18 19
20
21
22
23
24
25
26
27
28
29
30
31
32
33

Page 4
Section 1
Introduction
Description
The AxleTech PRC 416-P and PRC 756-P planetary
axles incorporate a single reduction carrier/
differential assembly with hypoid gearing. They
are equipped with the RS-145 carrier series. The
final reduction is of planetary spur designed
gearing built into the wheel hubs. The axles have
only cast housings. Figure 1.1.
AxleTech Planetary Axles permit the hypoid
gearing of the carrier and the axle shafts to carry
only a nominal torsional load. At the same time,
they provide the highest practical numerical gear
reduction at the wheels.
•The hypoid pinion and differential assembly of
the first reduction supports the roller bearings.
•A hardened precision spacer between the
inner and outer bearings adjusts and
maintains the pinion bearing preload.
•The positioning of the threaded adjusting rings
in the carrier leg and cap bores adjusts and
maintains the differential tapered bearing
preload.
Figure 1.1
•The teeth of the floating sun gear mesh with
teeth of the planetary spur gears.
•The planetary gears rotate on planetary shafts
that are mounted on a spider. The planetary
gear teeth in turn mesh with teeth of the
floating ring gear.
•The hypoid gear set in the carrier drives the
wheel hub. The gear transmits power to the
axle shafts and the sun gear of the final
reduction, through the revolving planetary
gears, and into the planetary spider.
PRC 416-P

Page 5
Section 1
Introduction
Identification
The exact axle model specification is shown on
the identification tag located on the axle.
Figure 1.2.
SINGLE PLANETARY AXLES
Figure 1.2
P R C 7 5 6 P 208
EXACT
SPECIFICATION
R – RIGID
S – STEERING
P – PLANETARY
N – NON-DRIVE
LAST DIGIT:
CARRIER
DESIGNATION
FOR BASE MODEL
NUMBER
FIRST TWO OR THREE
DIGITS: WHEEL END
DESIGNATION
(BASIC MODEL
NUMBER)
HOUSING TYPE
DESIGNATION:
C – INTEGRAL CAST
S – STAMPED
A – POT OR SPLIT CARRIER
ONLY IF APPLICABLE:
T–
TRANSMISSION ON CARRIER
O– OSCILLATING OR PIN MOUNT
L–MOUNTING OTHER THAN PAD
WITH DRILLING
BRAKE TYPE:
H— HYDRAULIC DRUM
M— MECHANICAL DRUM
N— NONE
NR — WITH ROTOR LESS CALIPERS
P— CAM-MASTER
®
“P” SERIES CAM
DLH — 17 in. (432 mm) HYDRAULIC DRUM - (DUAL LEADING
HYDRAULIC)
DSH — 12.5 in. (318 mm) HYDRAULIC DRUM (DUO-SERVO
HYDRAULIC)
FSH — FLOATING SHOE HYDRAULIC
HDB — HYDRAULIC DRY DISC
ADB — DURA-MASTER
®
AIR DISC
RDA — STOPMASTER
®
WEDGE (DUAL AIR CHAMBER)
RDH — STOPMASTER
®
WEDGE (DUAL HYDRAULIC
CYLINDERS)
RSA — STOPMASTER
®
WEDGE (SINGLE AIR CHAMBER)
RSH — STOPMASTER
®
WEDGE (SINGLE HYDRAULIC
CYLINDERS)
W2H — DURA-DISC
®
9 in. (229 mm) WET DISC
W3H — DURA-DISC
®
13 in. (330 mm) WET DISC
W4H — DURA-DISC
®
17 in. (432 mm) WET DISC
W5H — DURA-DISC
®
22 in. (560 mm) WET DISC
W2M — DURA-DISC
®
9 in. (229 mm) WET DISC SPRING
APPLIED HYDRAULIC RELEASE
W4M — DURA-DISC
®
17 in. (432 mm) WET DISC SPRING
APPLIED HYDRAULIC RELEASE
WDH330 — DURA-DISC
®
13 in. (330 mm) WET DISC (UNIT MOUNT)
WDH432 — DURA-DISC
®
17 in. (432 mm) WET DISC (UNIT MOUNT)
WDH560 — DURA-DISC
®
22 in. (560 mm) WET DISC (UNIT
MOUNT)
WDM — DURA-DISC
®
17 in. (432 mm) WET DISC (UNIT
MOUNT) SPRING APPLIED HYDRAULIC RELEASE

Page 6
Section 2
Removal and Disassembly –
PRC 416-P Planetary Axle
Remove and Disassemble
the PRC 416-P Planetary Axle
Wheel End
Figure 2.1.
Remove the Brake Drum
WARNINGS
To prevent serious eye injury, always wear
safe eye protection when you perform vehicle
maintenance or service.
Block the wheels to prevent the vehicle from
moving. Support the vehicle with safety stands.
Do not work under a vehicle that is supported
only by jacks. Jacks can slip or fall over. Serious
personal injury can result.
!
!
1. Make sure the vehicle is on a level surface.
2. Place blocks under the wheels not being
serviced to keep the vehicle from moving.
3. Raise the vehicle so that the wheels of the axle
to be serviced are off the ground. Support the
vehicle with safety stands. Refer to the vehicle
maintenance manual for instructions on
raising the vehicle.
4. Remove the wheel nuts and dual tire/rim
assemblies from both wheel ends.
5. Rotate the wheel ends so the magnetic drain
plug in the planetary spider is at the bottom.
Remove the plug. Drain and discard the
lubricant from both wheel ends.
Figure 2.1 PRC 416-P WHEEL END CROSS SECTION

Page 7
Section 2
Removal and Disassembly –
PRC 416-P Planetary Axle
6. If necessary, remove the magnetic drain plug
from the bottom of the axle housing. Drain
and discard the lubricant from the carrier
center section.
WARNING
When you work on a spring chamber, carefully
follow the service instructions of the chamber
manufacturer. Sudden release of a compressed
spring can cause serious personal injury.
7. If the brake air chamber assembly has a spring
chamber unit, carefully cage and lock the
spring to prevent the spring from activating
during disassembly.
NOTE
If Meritor automatic slack adjusters are used,
refer to Meritor Maintenance Manual No. 4B,
Automatic Slack Adjuster for the correct
adjustment procedure. To order this publication,
call Meritor’s Customer Service Center at
800-535-5560.
8. Adjust the brake slack adjuster to retract the
brake shoes to produce clearance between the
lining and the brake drum.
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
!
!
9. Use a lifting device to support the brake
drum. Figure 2.2.
NOTE
• Before 1996, brake drums incorporated
0.375-16 UNC threaded holes.
• Since 1996, brake drums are manufactured
with 0.500-13 UNC threaded holes.
• Optional drums with M12 x 1.75 threaded
holes are available.
10. Install capscrews into the threaded holes in
the brake drum. Gradually tighten the
capscrews in equal amounts to push the
drum off the pilot surface of the planetary
spider.
Figure 2.2

Page 8
Section 2
Removal and Disassembly –
PRC 416-P Planetary Axle
11. With the lifting device, carefully remove the
brake drum. Figure 2.3.
12. Remove the five slotted head screws that
attach the planetary spider to the wheel hub.
Remove the Planetary
Spider Assembly
NOTE
If only the planetary pinions are removed for
inspection without removing the pinion shaft,
proceed to Step 5.
1. With a lifting device, remove the planetary
spider from the wheel hub. Set its large
flange side on a work bench.
2. Mark the outer ends of the pinion shafts and
the planetary spider to aid in reassembly if
the original pinion shafts are used.
3. Remove the set screw from each of the
pinion shafts.
WARNINGS
Observe all warnings and cautions provided
by the press manufacturer to avoid damage to
components and serious personal injury.
Use a brass or leather mallet for assembly
and disassembly procedures. Do not hit steel
parts with a steel hammer. Pieces of a part can
break off and cause serious personal injury.
CAUTION
To avoid damage to the pinion shaft, provide a
soft cushioned area to receive the pinion shaft
when it is removed from the spider.
4. Use a press to remove the pinion shafts. If a
press is not available, use a brass drift and
mallet to drive out the shaft. Press or drive
the pinion shaft out toward the large flange
end of the planetary spider.
5. Remove the snap ring, inner thrust washer,
planetary pinion and outer thrust washer
from each pinion shaft.
6. Remove the axle shaft button only if it is
worn. Press it out toward the large end of the
planetary spider.
NOTE
The sun gear thrust washer may come out with
the axle shaft and sun gear assembly.
7. Remove the axle shaft, planetary sun gear
and snap ring assembly.
8. If necessary, remove the snap ring from the
axle shaft to allow for the removal of the sun
gear and sun gear thrust washer.
9. If necessary, remove the sun gear thrust
washer from the end of the planetary ring
gear.
10. Remove the planetary ring gear.
11. Remove the wheel bearing adjusting nut.
!
!
!
Figure 2.3

Page 9
Section 2
Removal and Disassembly –
PRC 416-P Planetary Axle
CAUTION
The outer bearing cone will be loose as you pass
it over the end of the spindle. Hold the cone
securely to avoid dropping it and damaging the
cone.
12. Remove the wheel hub assembly. The wheel
bearings and oil seal will come off with the
wheel hub.
CAUTION
Do not damage the hub oil seal bore surface in
the wheel hub. Damage to this surface will result
in oil leakage after assembly.
13. Remove the wheel hub oil seal from the
wheel hub.
14. Remove the inner bearing cone.
15. If replacement of the wheel bearings is
necessary, press out the outer bearing cup
and inner bearing cup from the hub.
16. Remove and discard the O-ring from the
wheel hub.
Disassemble the Brake
To disassemble the P Series brake, refer to
Meritor Maintenance Manual No. 4, Cam Brakes.
To order this publication, call Meritor’s Customer
Service Center at 800-535-5560.
NOTE
If it is necessary to remove the anchor pins,
remove the brake dust shields for convenient
access to the anchor pins.
!
!
Remove the Spindle and
Brake Spider
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting loops or lifting straps to
any shock or drop loading.
WARNING
Removal of the capscrews allows the spindle and
brake assembly to separate. They can fall from
the planetary axle housing and cause damage to
components and serious personal injury.
1. To prevent the spindle and the brake spider
from falling after all the mounting capscrews
are removed, use one of the following
procedures:
a. Use a lifting device to support the spindle
during disassembly.
b. Remove only two capscrews. Replace them
with two temporary 0.75 inch-10 UNC
thread studs 4 inches (102 mm) before the
remaining capscrews are removed.
— Install one stud at the 11 o’clock
position.
— Install one stud at the one o’clock
position.
2. Remove the two capscrews and washers that
mount the clamp around the brake camshaft
housing tube to the axle housing.
3. Remove the capscrews and washers that
mount the brake spider and spindle to the axle
housing.
4. Remove the brake spider and air chamber
assembly from the spindle.
5. Remove the spindle from the axle housing. If
necessary, tap lightly on the spindle to loosen
the pilot fit and to overcome the adhesion due
to cured gasket material in the flange joint.
!
!

Page 10
Section 3
Removal and Disassembly –
PRC 756-P Planetary Axle
Remove and Disassemble
the PRC 756-P Planetary Axle
Wheel End
Figure 3.1.
Remove the Brake Drum
WARNINGS
To prevent serious eye injury, always wear
safe eye protection when you perform vehicle
maintenance or service.
Block the wheels to prevent the vehicle from
moving. Support the vehicle with safety stands.
Do not work under a vehicle that is supported
only by jacks. Jacks can slip or fall over. Serious
personal injury can result.
!
!
1. Make sure the vehicle is on a level surface.
2. Place blocks under the wheels not being
serviced to keep the vehicle from moving.
3. Raise the vehicle so that the wheels of the axle
to be serviced are off the ground. Support the
vehicle with safety stands. Refer to the vehicle
maintenance manual for instructions on
raising the vehicle.
4. Remove the wheel nuts and dual tire/rim
assemblies from both wheel ends.
5. Rotate the wheel ends so the magnetic drain
plug in the planetary spider is at the bottom.
Remove the plug. Drain and discard the
lubricant from both wheel ends.
Figure 3.1 PRC-756 WHEEL END CROSS SECTION

Page 11
Section 3
Removal and Disassembly –
PRC 756-P Planetary Axle
6. If necessary, remove the magnetic drain plug
from the bottom of the axle housing. Drain
and discard the lubricant from the carrier
center section.
WARNING
When you work on a spring chamber, carefully
follow the service instructions of the chamber
manufacturer. Sudden release of a compressed
spring can cause serious personal injury.
7. If the brake air chamber assembly has a spring
chamber unit, carefully cage and lock the
spring to prevent the spring from activating
during disassembly.
NOTE
If Meritor automatic slack adjusters are used,
refer to Meritor Maintenance Manual No. 4B,
Automatic Slack Adjuster for the correct
adjustment procedure. To order this publication,
call Meritor’s Customer Service Center at
800-535-5560.
8. Adjust the brake slack adjuster to retract the
brake shoes to produce clearance between the
lining and the brake drum.
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
9. Use a lifting device to support the brake
drum. Figure 3.2.
!
!
NOTE
• Before 1996, brake drums incorporated
0.375-16 UNC threaded holes.
• Since 1996, brake drums are manufactured
with 0.500-13 UNC threaded holes.
• Optional drums with M12 x 1.75 threaded
holes are available.
10. Install capscrews into the threaded holes in
the brake drum. Gradually tighten the
capscrews in equal amounts to push the
drum off the pilot surface of the planetary
spider.
11. With the lifting device, carefully remove the
brake drum.
12. Remove the five slotted head screws that
attach the planetary spider to the wheel hub.
Figure 3.2

Page 12
Section 3
Removal and Disassembly –
PRC 756-P Planetary Axle
Remove the Planetary
Spider Assembly
1. With a lifting device, remove the planetary
spider assembly from the wheel hub and set
it on a work bench. Rest the spider on its
large flange end.
2. Remove the capscrews and washers that
mount the cover to the planetary spider.
Remove the cover.
3. If the axle shaft thrust button requires
replacement, support the planetary spider
cover in the area immediately adjacent to the
thrust button. Press the thrust button out of
the cover.
4. If the planetary ring gear did not remain with
the planetary spider assembly during the
assembly’s removal, remove the ring gear
from the planetary ring gear hub.
5. Mark the large ends of the planetary pinion
shafts and the planetary spider to aid in
reassembly if the original pinion shafts are
used.
6. Place the planetary spider assembly on
blocks with the large flange end facing
UPWARD.
WARNINGS
Observe all warnings and cautions provided
by the press manufacturer to avoid damage to
components and serious personal injury.
Use a brass or leather mallet for assembly
and disassembly procedures. Do not hit steel
parts with a steel hammer. Pieces of a part can
break off and cause serious personal injury.
CAUTION
To avoid damage to the pinion shaft, provide a
soft cushioned area to receive the pinion shaft
when it is removed from the spider.
7. Use a press to remove the pinion shafts out
of the spider. If a press is not available, use a
brass drift and mallet to drive out the shaft.
Press or drive the pinion shaft out toward the
small end of the spider which faces
DOWNWARD.
8. Remove the planetary pinions and thrust
washers from the planetary spider.
9. Remove the axle shaft, planetary sun gear
and snap ring assembly.
NOTE
The sun gear thrust washer may come out with
the axle shaft and sun gear assembly.
10. Remove the snap ring from the axle shaft to
allow for the removal of the sun gear from
the axle shaft.
11. If necessary, remove the sun gear thrust
washer from the axle shaft.
12. If necessary, remove the sun gear thrust
washer from the end of the spindle.
13. Remove the two lock plate capscrews.
Remove the lock plate from the planetary
ring gear hub.
14. Remove the wheel bearing adjusting nut.
15. Remove the planetary ring gear hub. The
outer wheel bearing cone will remain on the
ring gear hub. If it is damaged, remove it
from the hub.
16. Remove the wheel hub. The hub oil seal and
inner bearing assembly will remain in the
hub.
!
!
!

Page 13
Section 3
Removal and Disassembly –
PRC 756-P Planetary Axle
CAUTION
Do not damage the hub oil seal bore surface in
the wheel hub. Damage to this surface will result
in oil leakage after assembly.
17. Remove the hub oil seal.
18. Remove the inner bearing cone.
19. If replacement of the wheel bearings is
necessary, press out the outer bearing cup
and inner bearing cup.
20. Remove and discard the O-ring from the
wheel hub.
Disassemble the Brake
To disassemble the P Series brake, refer to
Meritor Maintenance Manual No. 4, Cam Brakes.
To order this publication, call Meritor’s Customer
Service Center at 800-535-5560.
NOTE
If it is necessary to remove the anchor pins,
remove the brake dust shields for convenient
access to the anchor pins.
!
Remove the Spindle and Brake
Spider
WARNINGS
To prevent serious personal injury and
possible damage to components, be very careful
when using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
Removal of the capscrews allows the spindle
and brake assembly to separate. They can fall
from the planetary axle housing and cause
damage to components and serious personal
injury.
1. To prevent the spindle and the brake spider
from falling after all the mounting capscrews
are removed, use one of the following
procedures:
a. Use a lifting device to support the spindle
during disassembly.
b. Remove only two capscrews. Replace them
with two temporary 0.75 inch-10 UNC thread
studs 4 inches (102 mm) long before the
remaining capscrews are removed.
— Install one stud at the 11 o’clock position.
— Install one stud at the one o’clock
position.
2. Remove the two capscrews and washers that
mount the clamp around the brake camshaft
housing tube to the axle housing.
3. Remove the capscrews and washers that
secure the brake spider and spindle to the axle
housing.
4. Remove the brake spider and air chamber
assembly from the spindle.
5. Remove the spindle from the axle housing. If
necessary, tap lightly on the spindle to loosen
the pilot fit and to overcome adhesion due to
cured gasket material in the flange joint.
!
!

Page 14
Section 4
Prepare Parts for Assembly
Clean Ground or Polished
Parts
WARNINGS
To prevent serious eye injury, always wear
safe eye protection when you perform vehicle
maintenance or service.
Solvent cleaners can be flammable,
poisonous and cause burns. Examples of solvent
cleaners are carbon tetrachloride, emulsion-type
cleaners and petroleum-based cleaners. To avoid
serious personal injury when you use solvent
cleaners, you must carefully follow the
manufacturer’s product instructions and these
procedures:
•Wear safe eye protection.
•Wear clothing that protects your skin.
•Work in a well-ventilated area.
•Do not use gasoline or solvents that contain
gasoline. Gasoline can explode.
•You must use hot solution tanks or alkaline
solutions correctly. Follow the manufacturer’s
instructions carefully.
CAUTION
•Use only solvent cleaners to clean ground or
polished metal parts. Hot solution tanks or
water and alkaline solutions will damage
these parts. Isopropyl alcohol, kerosene or
diesel fuel can be used for this purpose.
•If required, use a sharp knife to remove
gasket material from parts. Be careful not to
damage the ground or polished surfaces.
1. Use a cleaning solvent, kerosene or diesel
fuel, to clean ground or polished parts or
surfaces. NEVER USE GASOLINE.
2. Remove gasket material from parts. Take care
not to damage ground surfaces.
3. DO NOT clean ground or polished parts in a
hot solution tank, water, steam or alkaline
solution.
!
!
!
Clean Parts With Rough Finish
1. Use cleaning solvent or a hot solution tank
with a weak alkaline solution to clean parts
with a rough finish.
2. Leave parts in the hot solution tank until they
are completely cleaned and heated. When the
parts are clean, remove them from the tank.
3. Wash the parts with water until you
completely remove the alkaline solution.
Clean Axle Assemblies
•A complete axle assembly can be steam
cleaned on the outside to remove dirt.
•Before the axle is steam cleaned, close or put
a cover over all openings in the axle
assembly. Examples of openings are
breathers or vents in air chambers.
CAUTION
Dry bearings with clean paper or rags. Do not
use compressed air, which can cause abrasive
particles to contaminate bearings. Damage to
components and reduced lining life can result.
Dry Cleaned Parts
•Immediately after cleaning, use clean paper,
rags or compressed air to dry parts.
Prevent Corrosion
NOTE
Parts must be clean and dry before you lubricate
them.
1. If you assemble parts immediately after you
clean them: Lubricate clean, dry parts with
grease to prevent corrosion.
2. If you store parts after you clean them: Apply
a corrosion-preventive material to all
machined surfaces. Store parts in a special
paper or other material that prevents
corrosion.
!

Page 15
Section 4
Prepare Parts for Assembly
Inspect Parts
•It is important to carefully inspect all parts for
wear and damage before you assemble the
axle carrier.
•Replace damaged parts.
Inspect Tapered Roller Bearings
Inspect the cup, cone, rollers and cage of all
tapered roller bearings in the assembly. If any of
the following conditions exist, replace the
bearing:
•The centers of the large diameter end of the
rollers are worn level with or below the
surface.
•The centers of the large diameter end of the
rollers are worn to a sharp edge. Figure 4.1.
•A visible roller groove is worn in the cup or
cone inner race surfaces. You can see the
groove at the small or large diameter ends of
both parts. Figure 4.2.
Figure 4.2
Figure 4.1 WORN RADIUS
WORN SURFACE
CRACK WEAR GROOVES

Page 16
Section 4
Prepare Parts for Assembly
•Spalling or flaking is present on the cup and
cone inner race surfaces that touch the rollers.
Figure 4.5.
Inspect the Bevel Pinion and Ring
Gear Sets
CAUTIONS
Bevel drive pinions and ring gears are
machined in matched sets. When a drive pinion
or ring gear of a bevel set needs to be replaced,
both drive gear and pinion must be replaced at
the same time. A higher stress on original parts
and early failure of the entire assembly will result
if a new part is used in combination with parts
that are older or worn.
Inspect the bevel drive pinions and ring gears
for wear and damage. Gears that are worn or
damaged must be replaced. Also verify the
condition of the bearing cone seats and spline on
the pinion shaft.
!
!
•Deep cracks or breaks are present in the cup,
cone inner race or roller surfaces.
•Bright wear marks are present on the outer
surface of the roller cage. Figure 4.3.
•Etching and pitting is present on rollers and on
surfaces of the cup and cone inner race that
touches the rollers. Figure 4.4.
Figure 4.5 SPALLING AND
FLAKING
Figure 4.3
Figure 4.4
WEAR MARKS
ETCHING AND
PITTING