Chamberlain 7708CB User Manual
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.
Eight-Foot Rail Extension Kit
Model 7708CB
To prevent possible SERIOUS INJURY or DEATH:
• Disconnect ALL electric and battery power BEFORE performing
ANY service or maintenance.
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 1)
and discard.
5. Remove idler pulley assembly and set aside.
6. Remove the chain/cable assembly and discard.
7. 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 2).
8. 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.
9. As a temporary stop, insert a screwdriver into the hole 10" (25 cm)
from the front end of the rail (Figure 1). Slide the trolley assembly to
this point.
10. Locate the rail tab. Use a flathead screwdriver and lift the rail tab until
the tab is vertical (90°) (Figure 2).
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.
13. Make adjustments and test the safety reversal system according to the
owner's manual.
The garage door MUST be in the fully closed position during
installation.
Figure 1
Master
Link
Inner
Lock
Nut
Washer
Threaded
Shaft
Front Rail
Section
Idler Pulley
Outer
Nut
Figure 2
To remove rail pry both
end tabs of front
rail slightly outward
Rail Tab
NEW
FRONT RAIL
Rail Tab
CORRECT
INCORRECT
Master
Link
Idler Bolt hole
(KEEP LARGER
ONE ON TOP)
ADDING AN ADDITIONAL HANGING BRACKET:
Cut the enclosed hanging bracket (cross brace) to fit across the installed
hanging brackets. Fasten the cross brace to the top and bottom hole of the
hanging brackets (Figure 3 and Figure 4) using 5/16" -18x7/8" hex bolts,
5/16 lock washers and 5/16" -18 nuts.
To avoid possible SERIOUS INJURY from a falling garage door
opener, fasten it SECURELY to structural supports of the garage.
Concrete anchors MUST be used if installing any brackets into
masonry.
Figure 3 Figure 4
Hanging Bracket
(Cross Brace)
Lock Washer 5/16"
Nut 5/16"-18
Lock Washer 5/16"
Nut 5/16"-18
HARDWARE SHOWN ACTUAL SIZE
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
Lock Washer 5/16"
Nut 5/16"-18
REPLACEMENT PARTS
Part No. Description Qty
183C158-14 Header Rail Extension 1
41A5807-1 8' Chain/Cable Assembly 1
Hex Bolt
5/16"-18x7/8"
Nut 5/16"-18
Lock Washer 5/16"
41A3021 Rope 1
4A1008 Master Link Kit 1
Hanging Bracket
(Cross Brace)
Bolt 5/16"-18x7/8"
Hanging Bracket (Cross Brace) Not shown actual size
© 2013, The Chamberlain Group Inc.
114A2746F All Rights Reserved
Loading...