Craftsman 139.18451DM Manuel D'instructions page 16

INSTALLATION STEP 5
Hang the Opener
Three representative installations are shown. Yours may be
different. Hanging brackets should be angled (Figure 1) to provide
rigid support. On fi nished ceilings (Figure 2 and Figure 3), attach
a sturdy metal bracket to structural supports before installing the
opener. This bracket and fastening hardware are not provided.
1. Measure the distance from each side of the motor unit to the
structural support.
2. Cut both pieces of the hanging bracket to required lengths.
3. Drill 3/16" pilot holes in the structural supports.
4. Attach one end of each bracket to a support with
5/16"-18x1-7/8" lag screws.
5. Fasten the opener to the hanging brackets with 5/16"-18x7/8"
hex bolts, lock washers and nuts.
6. Check to make sure the rail is centered over the door (or in line
with the header bracket if the bracket is not centered above the
door).
7. Remove the 2x4. Operate the door manually. If the door hits the
rail, raise the header bracket.
NOTE: DO NOT connect power to opener at this time.
HARDWARE SHOWN ACTUAL SIZE
Lag Screw 5/16"-18x1-7/8"
Hex Bolt
5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
To avoid possible SERIOUS INJURY from a falling garage
door opener, fasten it SECURELY to structural supports of
the garage. Concrete anchors MUST be used if installing ANY
brackets into masonry.
Figure 1
Structural
Supports
Lag Screws
5/16"-18x1-7/8"
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
Hidden
Figure 2
Support
Bracket
(Not Provided)
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
Figure 3
Lag Screws
5/16"-18x1-7/8"
(Not Provided)
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
16
Measure
Distance
Lag Screws
5/16"-18x1-7/8"
FINISHED CEILING
(Not Provided)
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
FINISHED CEILING
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18