Assembly Section: Pages; Assemble Rail; Attach Chain Pulley Bracket - Chamberlain CSO Owner's Manual

To avoid installation difficulties, do not run the garage door opener until instructed to do so.
Assembly Step 1
Assemble the Rail &
Attach the Chain Pulley Bracket
• Align the 4 rail sections on a flat surface exactly as
shown. Center sections are interchangeable. Front
and back sections are not. Be sure the arrow
labels are pointing toward the door.
• Insert the carriage bolts so the square bolt necks
seat in the square holes in the rail sections and
pass through the square holes in the opposing rail
sections. Assemble lock nuts, ensure alignment
and tighten.
If rail is not assembled
exactly as shown, trolley
will not travel smoothly
along length of rail or it
will hit against nuts.
Chain pulley bracket
attaches to FRONT
END of Rail
RAIL FRONT
(TO DOOR)
• Position the chain pulley bracket on the front end
of the rail as shown. Fasten securely with the
hardware shown.
Hex Screws
5/16"-18x7/8"
Chain Pulley
Bracket
Nut - 5/16"
Assembly Section: Pages 7 – 10
Rail Assembly
(Center Section)
Rail Assembly
(Door End)
Lock Washer
5/16"
1/4" Lock
Nuts
Rail Assembly
(Center Section)
Hardware Shown Actual Size
Lock Nut
1/4"-20x7/16"
Hex Screw
5/16"-18x7/8"
Right
7
RAIL BACK
(TO POWER HEAD)
Rail Assembly
(Power Head End)
Carriage Bolt
1/4"-20x1/2"
Make sure bolt
necks are seated
in the square
holes and rails
are aligned
before you
tighten lock nuts.
Right
(See right and
wrong views).
Improper
assembly can
cause jerky
trolley operation,
noise and/or
nuisance door
reversals.
Wrong
Carriage Bolt
1/4"-20x1/2"
Nut Lock Washer
5/16"-18
When tightening
the screws, be
sure to keep
bracket parallel to
the rail. Otherwise,
the rail may bow
when the opener is
operated.
Wrong
5/16"