CSC-10026423-5899

PRODUCT INFORMATION LETTER
ArvinMeritor, Inc.
2135 West Maple Road
Troy, MI 48084-7186

PRODUCT INFORMATION LETTER #462 - Revised Aug 06
Date: July, 2006
Subject: Hub Reduction Wheel End Upgrade – 3 to 4 Planet Pinion Gears
Models: RC-26-633 and RC-26-634
Dear Customer,

DESCRIPTION OF UPGRADES
The RC-26-633 is a double reduction axle design incorporating a first stage reduction in the center carrier and second stage
in a planetary gear set at each wheel end. The planetary wheel ends have used 3 planetary pinion gears since the axle was
launched in North America. This will be upgraded to a 4 planet pinion design. There are also changes to the thrust washer
and coupling used in the wheel ends to improve wear resistance and lubrication flow. The upgraded axle will be designated
as model number RC-26-634.
The parts in each wheel end that are being upgraded are as follows.
•
•
•
•

Planetary Spider (Revised to add 4th planet pinion gear)
Thrust Washer - Coupling (Larger diameter)
Thrust Coupling (Lubrication grooves in thrust surface).
Thrust Washer – Planetary Pinion Gear (different shape washer)

See page 3 for pictures.
OEM PRODUCTION LAUNCH
Production for the RC-26-634 commenced February 2006. The RC-26-633 became no longer available after this date.
New axle specification numbers are required. Contact your Account Manager to coordinate the change to the new
specifications.
SERVICE INFORMATION
Full Wheel End Rebuild
For full wheel end rebuild, ArvinMeritor is discontinuing service kits for the 3 planet gear wheel end and replacing with
kits using the 4 planet design. Kit part numbers are below. See page 4 for parts included. Kits can be ordered through
normal Aftermarket channels.
•
•

RC26634 330 (for rebuild of wheel ends having 3.30 ratio).
RC26634 355 (for rebuild of wheel ends having 3.55 ratio).

Note: For 60’ articulated buses ArvinMeritor advises that both left and right wheel ends be upgraded to optimize wheel
end life.
For 40’ standard buses, ArvinMeritor suggests that both wheel ends be upgraded; however, in cases where only one wheel
end requires repair, it is acceptable to upgrade one side only to the 4 planet design.

PRODUCT INFORMATION LETTER

PRODUCT INFORMATION LETTER

PRODUCT INFORMATION LETTER

This Product Information Letter describes upgrades to the hub reduction wheel ends on ArvinMeritor model RC-26-633
axles used in certain transit bus applications in North America.

Partial Wheel End Rebuild
ArvinMeritor will still make certain parts available to service the 3 planet wheel ends where partial wheel
end part replacement is necessary. See chart below for part number information.
Partial Wheel End Rebuilds Parts Information
3 planet
4 planet
Comments
design
design
Thrust Washer
SA75101174 SA88350358 If 3 planet washer is ordered will be
Withdraw
upgraded to KIT 6052 with 4 planet thrust
washer and thrust coupling.
Thrust Coupling
SA88350245 SA88350357 If 3 planet coupling is ordered will be
Withdraw
upgraded to KIT 6052 with 4 planet thrust
washer and thrust coupling.
Planet Pinion Thrust
SA88350005 SA65011973 Thrust washer unique to each design. Retain
Washer
Retain
each for individual part service.
Planetary Spider Assembly SA65011573 SA88423435 Planetary Spider Assemble unique for 3 and
(3.30 ratio)
Retain
4 planet design. Retain each for service.
Planetary Spider Assembly SA65011469 SA88423433 Planetary Spider Assembly unique for 3 and
(3.55 ratio)
Retain
4 planet design. Retain each for service.
Item

Service Manuals
Procedures outlined in ArvinMeritor Maintenance Manual MM23E can be used for both the 3 and 4 planet
rebuild. ArvinMeritor advises that during rebuild close inspection of all wheel end components be made
for unusual wear and replaced especially when mating with new parts. Examples are splined connections,
sun gear & planetary pinions, and thrust washer & couplings.
FINAL CONSIDERATIONS & RECOMMENDATIONS
COMPATABILITY WITH RETARDERS
City buses using transmission retarders put additional load on axle gearing and bearings while decelerating
the bus. ArvinMeritor advises transmission retarders be adjusted to the lowest setting to maximize axle
performance.
•
•

Allison B400R set to low setting of 1100 ft-lb torque
Allison B500R set to low setting of 2000 ft-lb torque

We also recommend retarders be activated by brake application only (not off throttle release) and to utilize
the first and second stages (33% and 66% of full torque setting). These adjustments to retarder settings and
activation stages will optimize axle durability in frequent stop-start duty cycle for transit buses.
Contact your ArvinMeritor representative for further information.

Glen Swanson
Glen Swanson
Product Manager

Planetary Spider

Planetary Pinion Thrust
Washer

Thrust Coupling

Thrust Washer
(Section View)

Description
THRUST COUPLING
THRUST WASHER

Description
SCREW-THRUST
GEAR-SUN
PLUG
SEAL
CAPSCREW
SCREW
NUT
SCREW
THRUST-END
THRUST
COUPLING
THRUST WASHER
PLNT-SPIDER-4AY

Description
SCREW-THRUST
GEAR-SUN
PLUG
SEAL
CAPSCREW
SCREW
NUT
SCREW
THRUST-END
THRUST COUPLING
THRUST WASHER
PLNT-SPIDER-4AY

Thrust Washer & Thrust Coupling KIT 6052
Part Number
Quantity/Wheel End
SA88350357
1
SA88350358
1
RC26634 330 Wheel End Rebuild Kit Contents
Part Number
Quantity/
Comments
Wheel End
41X1366
1
SA65011574
1
SA75503039
1
SA75503675
1
SA75503727
8
SA75503792
1
SA75503913
1
SA75504044
1
SA88350250
1
SA88350357
1
SA88350358
SA88423435

1
1

Includes planetary spider, pinion gears,
and thrust washers

RC26634 355 Wheel End Rebuild Kit Contents
Part Number
Quantity/Wheel End
41X1366
1
SA65011377
1
SA75503039
1
SA75503675
1
SA75503727
8
SA75503792
1
SA75503913
1
SA75504044
1
SA88350250
1
SA88350357
1
SA88350358
1
SA88423433
1