Chamberlain 7220 1/2HP - Manual (Page 8)

8
ASSEMBLY STEP 1
Assemble the T-Rail and
Attach the Cable Pulley Bracket
To avoid installation difficulties, do not run the
garage door opener until instructed to do so.
1. Align the four T-rail sections on a flat surface
exactly as shown. Center sections are
interchangeable. Front and back sections are also
interchangeable for ease of assembly.
2. Insert the carriage bolts so the square
bolt necks seat in the square holes in
the T-rail sections and pass through
the round holes in the rail braces.
Make sure bolt necks are seated in
the square holes and rails are
aligned before you tighten lock
nuts. Improper assembly can cause
jerky trolley operation, noise and/or
nuisance door reversals.
3. Assemble lock nuts, ensure alignment and
tighten.
NOTE: If T-rail is not assembled exactly as shown,
trolley will not travel smoothly along length of rail
or it will hit against nuts.
4. Position the cable pulley bracket on the front end
of the T-rail as shown. Fasten securely with the
hardware shown.
NOTE: When tightening the screws, be sure to
keep bracket parallel to the rail. Otherwise, the rail
may bow when the
opener is operated.
T-RAIL BACK
(TO MOTOR UNIT)
T-RAIL FRONT
(TO DOOR)
Cable pulley bracket
attaches to FRONT
END of T-rail
T-rail
(End Section)
T-rail
(Center Section)
Carriage Bolt
1/4"-20x1/2"
T-rail
(End Section)
Square Carriage
Bolt Hole
1/4" Lock Nut
Hex Screws
5/16"-18x7/8"
Cable Pulley
Bracket
Bracket & Rail Must Be Aligned
Lock Washer
5/16"
Nut
5/16"-18
Lock Nut
1/4"-20
Carriage Bolts
1/4"-20x1/2"
Hex Screw
5/16"-18x7/8" Nut
5/16"-18 Lock Washer
5/16"
HARDWARE
SHOWN ACTUAL SIZE