d) Setting Tooth Backlash
The manufacturer has already pre-set the tooth back-
lash. Generally, corrections are not required.
However, it is possible that the attachment screws of
the motor will come loose due to vibrations after ex-
tended operation of the vehicle.
In this case, it is necessary to screw on the motor
again; however, observe that the tooth backlash must
be set properly.
Pull out the two clips (A); then the dust protection cover
(B) can be taken off.
The distance between the main gear (C) and motor pin-
ion (D) generally must be as low as possible without the
gears being too tight.
Loosen the motor attachment screws (E) slightly. Then
push the motor with the motor pinion (D) in the direction
of the main gear (C) with light pressure.
The motor must not wobble during this; the
attachment screws must only be released
until the motor can be moved.
The motor pinion and the main gear now engage with-
out clearance. However, this is not perfect for the ser-
vice life of the gears!
Put a thin paper strip (F) between the main gear (C)
and the motor pinion (D). Then manually turn the main
gear so that the paper strip (max. 80 g paper!) is pulled
in between the two gears.
The pressure of the paper pushes back the electric mo-
tor by the required measure.
Now tighten the motor's attachment screws (E) again
in this position.
If you then turn back the main gear so that the paper
strip can be removed again (G), both gears should
have the correct distance.
Ideally, the motor pinion should be as close as possible to the main gear without the teeth touching and the
gears therefore being tight.
If the gears (motor pinion and main gear) are too far apart, the main gear teeth will be virtually shaved off
by the motor pinion after a few seconds - this will void the warranty/guarantee!
If the motor pinion presses against the main gear (gears are running without play), this will decrease perfor-
mance, increase power consumption (the motor already requires lots of power to turn the main gear) and
lead to premature wear.
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