PREVOST X3-45 VIP 2017, Owner'S Manual

Page: 111 / 212

Other Features 5-25
DRIVER CONTROLLED
DIFFERENTIAL LOCK (DCDL)
By actuating the electric switch, the driver can
lock or unlock differential action.
The purpose of the DCDL is to provide
maximum vehicle traction and control on
unfavorable road 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.
2. When the DCDL is locked, operate the
vehicle at low speeds. DCDL will not engage
and will disengage in speed higher than 5
MPH (8 km/h).
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.
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 occur.
LOCKING THE DCDL
When encountering poor road conditions where
maximum traction is needed, follow the
recommended procedures:
1. Without the wheels spinning, slipping or
losing traction, flip the DCDL control switch
to the “LOCK” position while maintaining a
constant vehicle speed.
2. Let up momentarily on the accelerator to
relieve torque on the gearing, allowing the
DCDL to lock.
3. When the DCDL is fully locked, the vehicle
will have an “understeer” condition when
making turns. Proceed cautiously over poor
road conditions.
UNLOCKING THE DCDL
When the vehicle can safely operate and driving
conditions have improved, disengage the DCDL
following the recommended procedures:
1. Flip the control switch to the “UNLOCK”
position, when the vehicle is stopped or
when traveling at low speed while the wheels
are not spinning, slipping or losing traction.
2. Let up momentarily on the accelerator to
relieve torque on the gearing, allowing the
DCDL to unlock.
3. Resume driving at normal speed using good
driving judgment.
RETRACTABLE TAG AXLE
The standard tag axle retraction system is
controlled by a valve located on the right lateral
console. The valve can be switched to either the
WHEELS UP or WHEELS DOWN position. The
axle will be raised or lowered by air pressure
according to the valve position. Refer to
"Controls & Instruments" chapter.
The tag axle service brakes operate only when
the tag axle is in the WHEELS DOWN position.
Never lower the tag axle while the coach is
moving. When the tag axle is in the WHEELS
UP position, the corresponding indicator light will
illuminate. The indicator light will start flashing
and an audible alarm will sound to warn the
driver if the vehicle speed exceeds 12 mph (20
km/h) with tag axle raised. The tag axle can be
raised in tight maneuvering areas like in a
parking lot or to make it easier to turn a short
corner. The tag axle shortens the wheelbase and
allows tighter turning. Raising the tag axle
transfers extra weight and additional traction to
the drive wheels providing improved control on
slippery roads.
CAUTION
Do not use tag axle in raised position for an
extended period. Raising tag axle increases
load on the drive axle, suspension and tires.
Do not drive vehicle with tag axle raised when
speed is exceeding 12 mph (20 km/h).
In order to prevent damage to the suspension,