Chamberlain LiftMaster 3275C Owner's Manual page 20

ONE-PIECE DOORS
Please read and comply with the warnings and reinforcement
instructions on the previous page. They apply to one-piece doors
also.
• Center the door bracket on the top of the door, in line with the
header bracket as shown. Mark either the left and right, or the
top and bottom holes.
• Metal Doors: Drill 3/16" pilot holes and fasten the bracket with
the 1/4"-14x5/8" self-threading screws provided.
• Wood Doors: Drill 5/16" holes and use 5/16"x2" carriage bolts,
lock washers and nuts (not provided) or 5/16"x1-1/2" lag
screws (not provided) depending on your installation needs.
NOTE: The door bracket may be installed on the top edge of the
door if required for your installation. (Refer to the dotted line
optional placement drawing.)
Header Wall
Finished Ceiling
2x4 Support
Header
Bracket
Door
Bracket
Optional
HORIZONTAL AND VERTICAL
Placement
REINFORCEMENT IS NEEDED
of Door
FOR LIGHTWEIGHT GARAGE
Bracket
DOORS (FIBERGLASS,
ALUMINUM, STEEL, DOORS
WITH GLASS PANEL, ETC.).
Vertical
(NOT PROVIDED)
Centerline of
Garage Door
For a door with no exposed framing,
or for the optional installation, use
lag screws 5/16"x1-1/2" (Not Provided)
to fasten door bracket.
Self-Threading Screw
1/4"-14x5/8"
Door
Bracket
Nut
5/16"-18
Door
Bracket
20
HARDWARE SHOWN
ACTUAL SIZE
Self-Threading
Screw
1/4"-14x5/8"
Top of Door
(Inside
Garage)
Top Edge
of Door
Optional
Placement
METAL DOOR
Lock
Washer
5/16"
Top of Door
(Inside
Garage)
Top Edge
of Door
Optional
Placement
Carriage Bolt
5/16"x2"
(Not Provided)
WOOD DOOR