Chamberlain 9902 - Manual (Page 19)

Installation Step 5
Position the Opener
Follow instructions which apply to your door type
as illustrated. To prevent damage to steel, aluminum, fiberglass or
glass panel doors, do not rest the opener on the door
without using a 2x4.
SECTIONAL Door or
ONE-PIECE Door with Track
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.
Rail 2x4
Door
Foam
Packaging
ONE-PIECE Door without Track
• 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.
Top of Opener
Header
Bracket
Top of Door
Foam
Packaging
19
CAUTION CAUTION
Trolley
Trolley
Release Arm