Instructions / Assembly
Model 7708CB
Eight-Foot Rail Extension Kit
BEFORE YOU BEGIN:
• The trolley must be in down (closed door) position during
assembly and installation. If you have a completely installed
garage door opener, the rail/opener assembly must be taken
down. UP and DOWN Limits must be readjusted after installation.
• Opener hanging brackets will require repositioning and the
addition of an extra bracket for stability due to increased
rail length.
IF THIS IS A NEW INSTALLATION:
Use the front (header) rail section, chain/cable assembly, and
longer emergency release rope in this kit in place of those
packaged with your garage door opener. Complete the assembly,
installation, and adjustment of your opener according to your
owner’s manual
, with the exception of adding an additional
hanging bracket for stability.
IF THIS IS AN EXISTING INSTALLATION,
CONTINUE AS FOLLOWS:
1. Pull down on the emergency release handle, then disconnect
the trolley from the door arm.
2. Disconnect the rail/opener assembly from the header bracket
and hanging brackets, and place it on the floor.
3. Remove the outer nut (Figure 1) from the trolley shaft and set
aside.
4. Disconnect the two master link assemblies from the trolley
(Figure 2) and discard.
5. Remove idler pulley assembly and set aside.
6. Remove the chain/cable assembly and discard.
7. Remove the 1/4"-20x1-3/4 bolt and lock nut from the trolley
stop hole in the front rail and set aside.
8. Push the trolley back toward the opener. Disconnect the front
rail section by using a screwdriver tip to pry up the outer tab on
each side of the rail, then slide it off the center rail. Discard the
front rail (Figure 3).
9. Align the new front rail with the existing rail assembly, keeping
the cut out “window” at the front (header) end. Be sure to keep
it right side up: the idler pulley bolt hole above the window is
larger on top of the rail than on the bottom. Slide the front rail
onto the assembly; tabs along the side will lock into place.
10. As a temporary trolley stop, clamp a locking pliers onto the rail,
8" (20 cm) from the center of the idler pulley hole (Figure 4).
Slide the trolley assembly to this point.
11. Refer to your owner’s manual to complete the assembly,
re-installation and adjustment of your opener. NOTE: Before
hanging the opener, an additional hanging bracket is necessary
for stability. See Adding An Additional Hanging Bracket on
reverse side. (Replace the old emergency release rope with the
new, longer replacement rope.)
12. Reconnect power and operate the door in the UP direction.
13. Increase the UP travel limit by turning the UP limit adjustment
screw in a clockwise direction as shown on label. One turn
equals 2" (5 cm) of travel.
Idler
Pulley
Slotted
Hole
Hole
Master Link
Clip-On Spring
Trolley
Threaded
Shaft
Master
Link Bar
Cable
Link
Cable
Pin
Notch
Master
Link Cap
Master
Link Bar
Trolley Stop Bolt
1/4"-20x1-3/4"
Figure 1
To prevent possible SERIOUS INJURY or DEATH:
• Be sure door is CLOSED and
• Disconnect power to opener BEFORE proceeding.
WARNING
CAUTION
WARNING
WARNING
ATTENTION
AVERTISSEMENT AVERTISSEMENT
AVERTISSEMENT
Outer Nut
Trolley Shaft
Inner Nut &
Lock Washer
Master Link
Master Lin
k
Figure 3
Window
Cut-Out
Locking
Pliers
Idler
Pulley
Bolt Hole
8" from
Idler Pulley
Hole
Trolley Stop
Hole
Extension
Rail
Figure 2
®
OWNER’S INSTRUCTIONS
Figure 4
Idler Bolt hole
(KEEP LARGER
ONE ON TOP)
NEW
FRONT RAIL
Trolley
Stop Hole
To remove rail pry both
end tabs of front
rail slightly outward