Automatic Locking Differential - Mercedes-Benz 300 SL Owner's Manual

Driving the vehicle with different size
tires will cause the wheels to rotate at
different speeds, therefore the
acceleration slip control will activate
(yellow ASR function indicator lamp in
instrument cluster comes on). For this
reason, all wheels, including the spare
wheel, must have the same tire size.
In winter operation, the maximum
effectiveness of the acceleration slip
control is only achieved with M + S
radial tires.
On vehicles equipped with acceleration
slip control, the brake pad wear
warning lamp indicates brake pad wear
for the front as well as the rear brakes.
Caution!
If the vehicle is towed with the front
axle raised, the key must not be in
steering lock position 2. Otherwise, the
acceleration slip control will
immediately be engaged and will apply
the rear wheel brakes.

Automatic Locking Differential

(ASD)
The automatic locking differential
engages when there is a difference in
speed (slip) between the front and rear
wheels of over 2 km/h (1.2 mph) and
the vehicle speed is less than 25 km/h
(15.5 mph). It will disengage at speeds
above 26 km/h (16.2 mph).
The yellow function indicator in the
speedometer comes on whenever there
is a difference in speed between the
front and rear wheels of over 2 km/h
(1.2 mph), warning of slippery road
conditions.
Note:
The automatic locking differential will
not engage at speeds above 25 km/h
(15.5 mph). However, above this
speed, a limited-slip effect of up to
35% is always present.
In steering lock position 2, the yellow
function indicator lamp and the yellow
ASD indicator lamp in the instrument
cluster should come on and then must
go out with the engine running.
If the ASD indicator lamp comes on
with the engine running, a malfunction
has been detected. We recommend that
you visit an authorized MERCEDES-
BENZ dealer as soon as possible to
have the ASD checked.
Notes:
When testing the parking brake on a
brake test dynamometer, turn off the
engine to avoid engaging the automatic
locking differential.
In winter operation, the maximum
efficiency of the automatic locking
differential can only be attained
through the use of M + S radial tires on
all four wheels.
91