Horizontal
track
Back
view
Front view
Spring restraint
cables
5/16” x 1-5/8”
Lag bolt
3 Hole
clip
Special
knot
3 Hole
clip
Rear back
hang
Extension
springs
Spring
restraint
cable
Extension
spring
Spring restraint
cable
5/16”-18 x 3-3/4”
Eye bolt
5/16”-18 x 3-3/4”
Eye bolt
Special
knot
3 Hole
clip
Rear
back
hang
Spring restraint
cable
Special
knot
5/16”-18 x 3-3/4”
Eye bolt
5/16”-18
Hex nut
Extension
spring
Horizontal track
5/16”-18
Hex nut
Horizontal track
5/16”-18
Hex nut
6”-8”
Attaching Spring Sheaves
17
IF YOU HAVE ONE PAIR OF EXTENSION SPRINGS:
Hook the sheave fork through the front
loop of the extension spring and attach the sheave fork to the rear cable lift sheave using (1)
3/8” - 16 x 1-1/4” hex head bolt and (1) 3/8” - 16 hex nut. Thread the counterbalance lift
cable over the front cable lift sheave and around the rear cable lift sheave and tie the special
knot around the “horizontal angle” using a 3 hole clip, as shown. Insert one end of the small
“S” hook into the “horizontal angle” with the 3 hole clip and the other end into the second
slot of the horizontal angle, as shown. Repeat for the other side.
Sheave fork
Extension spring
Rear cable
lift sheave
Spring
restraint
cable
3 Hole clip
Special
knot
Counterbalance
lift cable
Small
“S” hook
3/8”-16 x 1-1/4”
Hex head bolt
3/8” - 16
Hex nut
Sheave fork
Extension spring
Rear cable
lift sheave
Small
“S” hook
Horizontal
track
Rear back hang
Extension
spring
NOTE:
Some larger doors feature 2 pairs of extension springs. A spring restraint cable must
be installed through each spring.
IF YOU HAVE TWO PAIR OF EXTENSION SPRINGS:
Insert two large “S” hooks and the
sheave fork into the hook plate. Attach the sheave fork to the rear cable lift sheave using (1)
3/8” - 16 x 1-1/4” hex head bolt and (1) 3/8” - 16 hex nut. Thread the counterbalance lift
cable over the front cable lift sheave and around the rear cable lift sheave and tie the special
knot around the “horizontal angle” using a 3 hole clip, as shown. Insert one end of the small
“S” hook into the “horizontal angle” with the 3 hole clip and the other end into the second slot
of the horizontal angle, as shown. Insert one end of the small “S” hook into the “horizontal
angle” with the 3 hole clip and the other end into the second slot of the horizontal angle, as
shown. Repeat for the other side.
Horizontal
track
Spring restraint
cables
Rear back
hang
Extension
springs
3 Hole clip
Special
knot
Counterbalance
lift cable
Hook
plate
Extension
springs
Small
“S” hook
Large “S”
hooks
Small
“S” hook
3/8”-16 x 1-1/4”
Hex head bolt
3/8” - 16
Hex nut
Sheave
fork
Rear cable
lift sheave
IMPORTANT:
CLOSE “S” HOOKS AND EYE BOLTS WITH LOCKING PLIERS, TO PREVENT
SPRINGS FROM COMING LOOSE.
WARNING
FAILURE TO CLOSE “S” HOOKS AND EYE BOLTS CAN RESULT IN SEVERE
OR FATAL INJURY IF SPRINGS COME LOOSE.
Close
small “S”
hook
Close large
“S” hook
Close large
“S” hook
Small “S”
hook
Large “S”
hooks
Close
eye bolts
Eye bolts
Counterbalance Lift Cable Adjustments
18
Adjust counterbalance lift cables to create about 1” to 2” (25 mm to 50 mm) of initial exten-
sion spring stretch, with the door in the fully opened position. Measure relaxed extension
spring length for your door height and verify with the chart below. Spring length must be the
same for both extension springs to allow even door balance. Carefully remove the locking
pliers from the horizontal track and lower the door into the closed position. Once the door is
closed, measure the extension spring length in tension for both sides. Using the chart, verify
the spring length in tension is correct with your door height.
NOTE:
It may be necessary to adjust spring length for proper door balance.
Door Height
Spring Length Relaxed (Door
Open)
Spring Length Extended
(Door Closed)
6’ 0”
25” (635 mm)
61” (1549 mm)
6’ 3”
25” (635 mm)
62-1/2” (1588 mm)
6’ 6”
25” (635 mm)
64” (1626 mm)
9
Summary of Contents for EXTENSION 44
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