Craftsman 139.18451DM Manuel D'instructions page 8

ASSEMBLY STEP 1
Assemble the Rail & Install the Trolley
To avoid installation diffi culties, 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 fl at surface as shown and slide the
tapered ends into the larger ones. Tabs along the side will lock
into place.
Inner Trolley
Front Rail Section
(TO DOOR)
Outer Trolley
Wear Pads
Rail Tab
Idler
Pulley
Hole
Window
Cut-Out
To prevent INJURY from pinching, keep hands and fi ngers
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 stop, insert a screwdriver into the hole
10" (25 cm) from the front end 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.
7. Slide the rail onto the "U" bracket, until it reaches all the stops
on the top and sides of the "U" bracket.
Trolley
8
Back Rail Section
(TO MOTOR UNIT)
"U" Bracket
SLIDE TO STOPS
ON TOP AND
SIDES OF
"U" BRACKET