Examine the shuttle area.
If the shuttle belt is still mounted on the
pulleys, check the connectors, etc. at the Distribution PCA (J8
for the sensor and J10 for the Shuttle Motor) to ensure they are
seated completely. The shuttle sensor voltage can be checked at
J8 by turning the shuttle by hand and monitoring the voltage
with a voltmeter. If the voltage is not present, the problem
could be a bad shuttle sensor or shuttle sensor cable.
If the shuttle belt is off the pulleys, there
are a number of things to be checked:
1. CLEAN the shuttle belt with alcohol or
a good cleaning agent for rubber products. In some instances we
have seen belts that have a residue on them that will allow them
to slip off the pulleys.
2. Check the Pulley Alignment of the
pulleys on the shuttle motor and the shuttle assembly.
(Misalignment allows the belt to not track properly and to come
off the pulleys.) If you need to move one of the pulleys for
better alignment, the pulley on the shuttle motor is easier to
3. In some cases, the pulley on the shuttle
motor needs to be reversed to get the proper alignment (see
illustration). If you have to reverse the pulley, check the two
upper motor mounting screws to be sure they do not rub on the
shuttle belt. If it appears they may rub, install shorter
(These steps are also being done in production
beginning with December production - A21Lxxxxxx.)