Position The Opener - Craftsman 139.53491SRT Owner's Manual

Manual Disconnect
Liftmaster Screw Drive #114A1794
6/2/94, 6/15
Installation Step 5

Position the Opener

Follow instructions which apply to your door type
as illustrated.
A 2x4 laid flat is convenient for setting an ideal door-
to-rail distance.
• Raise the opener onto a stepladder.
You will need help at this point if the ladder is not tall
enough.
• Open the door all the way and place a 2x4 laid flat on
the top section beneath the rail.
If the top panel hits the trolley when you raise the door,
pull down on the trolley release arm to disconnect the
inner and outer sections. The trolley can remain
disconnected until Step 13 is completed.
• With the door fully open and parallel to the floor,
measure the distance from the floor to the top of the
door.
• Using a stepladder as a support, raise the opener to the
same distance as the door from the floor (it will be at a
slight angle as shown).
• The top of the door should be level with the top of the
opener. Do not position the opener more than 3" above
this point.
Step 3 Position Opener Chassis
114A1794 Lift-Master One Piece Rail
114A1794 Lift-Master One Piece Rail
5/9/94 - 6/1/94, 6/8/94 - 10/20/94
5/9/94 - 6/1/94, 6/8/94 - 10/20/94
SECTIONAL Door or ONE-PIECE Door with Track
Trolley
Release Arm
Emergency
Release
Handle
(Pull at 45° angle)
Trolley
Trolley
Release Arm
ONE-PIECE Door without Track
To prevent damage to steel, aluminum, fiberglass or
glass panel doors, do not rest the opener on the door
without using a 2x4.
Trolley
19
CAUTION
2x4
Rail
2x4
Rail
Foam
Door
Packaging
Foam
Door Packaging
Trolley
Trolley
ReleaseArm
(in Manual
Disconnect
Position)
Header
Bracket
Header
Bracket
Foam
Packaging
Foam
Top of Door
Packaging
Top of Door
Top of Opener
Top of Opener