Position The Opener - Chamberlain Series 651-2MM-1/2HP Owner's Manual

Installation Step 4

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-T-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 T-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 12 is
completed.
Trolley
• 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
2" above this point.
SECTIONAL Door & ONE-PIECE Door with Track
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.
T-rail
Door
Header
Bracket
16
CAUTION
2x4 Laid Flat
Stepladder
Top of Opener
Top of Door
Stepladder