80
46. Changing the toothed belt
Removal:
z Disconnect the machine lead cord.
z Remove needle and presser foot.
z Remove detachable work support.
z Remove top cover.
z Switch on bobbin winder.
z Remove the two Torx screws of the housing insert.
z Remove the housing insert.
z Remove the four retaining screws of the baseplate.
z Place the baseplate aside.
z Loosen screw 152 in arm shaft crank 153 (fig. 106).
z Loosen screw 1 on tensioning roller 2.
z Remove screw 154 on the upper toothed belt sprocket 155.
z Remove the circlip 156 from the arm shaft.
z Moving arm shaft 157 to the right, remove the toothed belt for the machine and the toothed belt for the
motor 59.
z Loosen the three screws 94, 95 and 96 on the automatic utility-stitch unit.
z Loosen the two screws 101 and remove small gear 97 to the right.
z Move the automatic utility-stitch unit a little to the front and remove toothed belt 158 between the large
gear and the shaft end.
Refitting:
z Insert the new toothed belt 158 for the machine between the large gear and the end of the shaft and
mount it on the lower belt sprocket 159.
z Tighten the three screws 94, 95 and 96 on the automatic utility-stitch unit.
z Pull toothed belt 158 upwards.
z Slide arm shaft 157 to the left through toothed belt 158 into the left bearing and arm shaft crank 153.
z Refit circlip 156 on the arm shaft.
z Secure the arm shaft and insert screw 152 in the arm shaft crank.
z Mount toothed belt 158 on the upper belt sprocket 155.
z Insert screw 154 in the upper belt sprocket and firmly tighten.
z Adjust tensioning roller in accordance with section 1.
z Mount toothed belt 59 for the motor on the handwheel.
z Refit small gear 97 on the shaft and gently tighten screws 101.
z Adjust the gears in accordance with section 22.
