SB-10043932-2343

PRODUCT INFORMATION LETTER #555
Date:

March 2012

Subject:

Meritor® Will Discontinue Offering RT-144, RT-145 and
MT-143 Series Tandem Drive Axles With Ductile Iron
Carriers Effective in July 2012

Models:

RT-34-144; RT-34-145, RT-40-145, RT-44-145; and MT-40143

Please be advised that effective in July 2012, Meritor will discontinue offering its RT-34-144,
RT-34-145, RT-40-145, RT-44-145 and MT-40-143 series tandem drive axles with ductile iron
carriers. The RT-144, RT-145 and MT-143 product lines will be replaced by the MT-14X series
that was launched in June 2010.
Meritor’s MT-14X series axle builds on the strengths of the RT-145 series axle and includes
enhanced features such as:


Larger main differential bearings for up to 30% more capacity.



A 20% larger inter-axle differential (IAD) for increased capacity to address higher engine
torques.



The smooth and efficient performance of our premium Amboid™ design, which reduces
universal joint operating angles for increased drivetrain life.



The industry’s fastest and most complete range of axle ratios – from 2.47 to 7.17 – and the
most efficient solution for vehicles with direct-drive transmissions.



The DualTrac™ housing option that addresses wheel-bearing overload associated with the
use of single wide base tires.

Orders for Meritor’s RT-144, RT-145 and MT-143 series tandem drive axles will be accepted
until April 16, 2012, for shipments occurring no later than June 30, 2012. Service parts and
remanufactured carriers for the RT-145 series axles will continue to be available through normal
aftermarket channels.
All aluminum versions of the current RT-145 family will continue to be available for production
until early 2013.
All single-axle nomenclature will convert from the “R” designation to the “M” designation for 1721,000 lbs GAWR axles.

PRODUCT INFORMATION LETTER #555 – Page 2
Standout Comparison
Refer to the chart and reference schematics to obtain position offset differences in the axle
model families.

Schematics (Reference)
Forward Carrier

PRODUCT INFORMATION LETTER #555 – Page 3
Rear Carrier

Housing

PRODUCT INFORMATION LETTER #555 – Page 4
Recommendations


Evaluate for potential driveline changes due to standout differences.



Update the axle nomenclature to the correct “M” designation.



Validate application approval, if required.

Please contact your Meritor account representative for additional information regarding the
changeover. For additional information on Meritor’s 14X series tandem drive axles and to
obtain the reference publications below, please visit the Literature on Demand section of
www.meritor.com.
Sean Gainey
Product Manager
Commercial Vehicle Systems

Reference Publications
Publication TP9441, Axle Application Guidelines, for information on Meritor’s MT-14X Series tandem drive
axles.
Publication TP7824, Component Reference Guide for Truck and Tractor Axle Specifications, Including
Transfer Cases.
Maintenance Manual MM0970, MT-14X Series Single-Reduction Forward Differential Carriers on Tandem
Axles.
Maintenance Manual MM0990, Amboid™ Rear Differential Carrier/Rear-Rear Carrier on MT-40-14X
Series Tandem Drive Axles.
Brochure SP1084, Meritor® 14X Tandem Drive Axle: The Next Evolution