Volvo VNL Operator's Manual page 317

312 Axles and Wheels
Engaging the differential locks must always
be done in the following way (see page 110
for switch location):
1 Depress the clutch pedal. Wait for the
drive wheels to stop spinning
2 Engage the differential lock
3 Engage a suitable gear
4 Carefully release the clutch pedal
Under normal traction conditions, do not
engage the differential locks. If at all possi-
ble, do not use the differential locks while
taking a curve. With good traction and the
differential locks engaged, the vehicle will
be understeered and therefore will tend to
drive straight in a curve. If the locks must
be used on good traction surface, drive cau-
tiously and do not exceed 25 mph
(40 km/h). Disengage the locks as soon as
possible.
When the differential locks are disengaged,
the couplings may be under tension. Disen-
gage the locks by returning the switch to
the OFF position. Help with the disengage-
ment by briefly letting up on the accelerator
to relieve the torque on the couplings.
The telltales for the differential locks are in
the instrument cluster. See page 86 for
more information on the telltales.
W3001991
W3000904