Craftsman 139.53910D Owner's Manual page 8

ASSEMBLY STEP 1
Assemble the Rail & Install the Trolley
To avoid installation difficulties, do not run the
garage door opener until instructed to do so.
The front rail has a cut out "window" at the door end
(see illustration). The hole above this window is
larger on the top of the rail than on the bottom. A
smaller hole 3-1/2" (8.9 cm) away is close to the rail
edge. Rotate the back rail so it has a similar hole
close to the opposite edge, about 4-3/4" (12 cm)
from the far end.
1. Remove the straight door arm and hanging
bracket packaged inside the front rail and set
aside for Installation Step 5 and 12. NOTE: To
prevent INJURY while unpacking the rail carefully
remove the straight door arm stored within the rail
section.
2. Align the rail sections on a flat surface as shown
and slide the tapered ends into the larger ones.
Tabs along the side will lock into place.
To prevent INJURYfrom pinching, keep hands and
fingers away from the joints while assembling the rail.
3. Place the motor unit on packing material to protect
the cover, and rest the back end of the rail on top.
For convenience, put a support under the front
end of the rail.
4. As a temporary trolley stop, insert a screwdriver
into the hole 10" (25 cm) away from the front of
the rail, as shown.
5. Check to be sure there are 4 plastic wear pads
inside the inner trolley. If they became loose
during shipping, check all packing material. Snap
them back into position as shown.
6. Slide the trolley assembly along the rail from the
back end to the screwdriver.
Trolley
_ered
End
KEEP LARGER
HOLE ON TOP
End
FRONT RAIL
(TOP)
tack Rails
(TO MOTOR UNIT)
End
Window
Cut-Out
Idler
Pulley-
Hole
Screwdriver
Tabs
Front Rail
(TO DO_R)_
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/
End
Inner Trolley
Wear Pads
Outer Trolle
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