TP-9646
Revised 11-18
TP-9646
(16579)
Revised 11-18
Printed in the USA
Copyright Meritor, Inc., 2018
Page 1
Technical Bulletin
Driver Controlled Main Differential
Lock (DCDL)
All Meritor Single Rear Drive
Axles with DCDL Option
Introduction
The Meritor Driver Controlled Main Differential Lock (DCDL) is an air-
actuated traction device that can be operated from the vehicle cab.
By actuating an air plunger or electric switch, usually mounted on
the instrument panel, the driver can lock or unlock main differential
action. When the DCDL is actuated, an indicator light on the
instrument panel will be on. When the DCDL is not actuated, the
indicator light will be off. Additional devices may also be used to
indicate the lock or unlock conditions, such as an audible signal.
Refer to the vehicle owner’s manual for DCDL operating instructions.
The purpose of the DCDL in a Meritor axle is to provide maximum
vehicle traction and control on unfavorable road or highway
surfaces. When the DCDL is actuated, a clutch collar completely
locks the differential case, gearing, and axle shafts together. This
feature maximizes traction to both wheels. The lock position will also
protect against spinout damage to the differential. The DCDL should
not be actuated when favorable road conditions exist.
Operation Tips
1.
The DCDL can be locked or unlocked if the vehicle is standing
still or moving at a constant low speed when the wheels are not
spinning, slipping, or losing traction. If a high torque or
spinning condition exists, relieve the condition by letting up on
the accelerator prior to engaging the DCDL switch.
2.
When the DCDL is locked, operate the vehicle at low speeds,
under 25 mph.
3.
When the DCDL is locked, the vehicle’s turning radius will
increase. This condition is called “understeer.” The driver must
use caution, good judgment and drive at low speeds when
operating the vehicle with the DCDL locked.
4.
Always unlock the DCDL as soon as the need for maximum
traction has passed and the vehicle is traveling on a good road
or highway.
5.
Do not lock the DCDL when the wheels are slipping or losing
traction, or damage to the axle can result.
6.
Do not lock the DCDL when the vehicle is traveling down steep
grades, or potential loss of vehicle stability could result in a
jackknife of tractor and trailer.
