Chamberlain 248735 3/4 HP Garage Door Opener User Manual


 
25
INSTALLATION STEP 12
Connect Door Arm to Trolley
Follow instructions which apply to your door type as
illustrated below and on the following page.
SECTIONAL DOORS ONLY
Make sure garage door is fully closed. Pull the
emergency release handle to disconnect the outer trolley
from the inner trolley. Slide the outer trolley back (away
from the pulley) about 8" (20 cm) as shown in Figures 1,
2 and 3.
Figure 1:
Fasten straight door arm section to outer trolley with
the 5/16"x1" clevis pin. Secure the connection with a
ring fastener.
Fasten curved section to the door bracket in the same
way, using the 5/16"x1-1/4" clevis pin.
Figure 2:
Bring arm sections together. Find two pairs of holes
that line up and join sections. Select holes as far apart
as possible to increase door arm rigidity.
Figure 3, Hole alignment alternative:
If holes in curved arm are above holes in straight arm,
disconnect straight arm. Cut about 6" (15 cm) from the
solid end. Reconnect to trolley with cut end down as
shown.
Bring arm sections together.
Find two pairs of holes that line up and join with bolts,
lock washers and nuts.
Pull the emergency release handle toward the opener at
a 45° angle so that the trolley release arm is horizontal.
Proceed to Adjustment Step 1, page 27. Trolley will
re-engage automatically when opener is operated.
Trolley
Stop Bolt
8" (20 cm) min.
8" (20 cm) min.
Trolley
Stop Bolt
Trolley
Stop Bolt
Ring
Fastener
Door
Bracket
Straight
Door Arm
Curved Door Arm
Inner
Trolley
Outer
Trolley
Lock
Washers
5/16"
Nuts
5/16"-18
Door Bracket
Bolts
5/16"-18x7/8"
Cut this end
Emergency
Release
Handle
Lock
Washers
5/16"
Nuts
5/16"-18
Bolts
5/16"-18x7/8"
Clevis Pin
5/16"x1"
Clevis Pin
5/16"x1-1/4"
Pulley
Pulley
Pulley
8" (20 cm
) min.
Figure 1
Figure 2
Figure 3
Lock Washer 5/16"
Nut 5/16"-18
Ring Fastener
Hex Bolt
5/16"-18x7/8"
Clevis Pin
5/16"x1" (Trolley)
Clevis Pin
5/16"x1-1/4" (Door Bracket)
HARDWARE SHOWN ACTUAL SIZE