Chamberlain AccessMaster M885 Installation Manual page 9

Installation
5 Hang the Garage Door Opener
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.
Hanging your garage door opener will vary depending on your garage. Two representative installations
are shown. Yours may be different. Hanging brackets should be angled (Figure 1) to provide rigid
support. On finished ceilings (Figure 2), 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 (not provided).
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
brackest 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.
Lock Washer 5/16"
FIGURE 1
Unfinished Ceiling
FIGURE 3
Measure
Distance
Hex Bolt 5/16"- 18x7/8", Lock Washer 5/16", Nut 5/16"-18
8
HARDWARE
Hex Bolt 5/16"- 18x7/8"
FIGURE 2
Finished Ceiling
Not Provided
(Not Provided)
Lag Screws
5/16"- 18x1-7/8"
Nut 5/16"-18