Chamberlain 3275 Garage Door Opener User Manual


 
21
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 door) about 2" (5 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.
IMPORTANT: The groove on the straight door arm MUST
face away from the curved door arm (Figure 4).
• 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 23. Trolley will
re-engage automatically when opener is operated.
HARDWARE SHOWN ACTUAL SIZE
Lock Washer 5/16"
Clevis Pin
5/16"x1" (Trolley)
Clevis Pin
5/16"x1-1/4" (Door Bracket)
Hex Bolt
5/16"-18x7/8"
Nut 5/16"-18
Ring Fastener
Emergency
Release
Handle
Straight
Door
Arm
Curved
Door
Arm
(Groove
facing out)
Straight
Door
Arm
Curved
Door
Arm
CORRECT INCORRECT
Figure 4
Figure 1
Figure 2
Figure 3
Outer Trolley
Inner Trolley
Clevis Pin
5/16"x1"
Ring
Fastener
Curved Door Arm
Door
Bracket
Straight
Door Arm
Nuts
5/16"-18
Nuts
5/16"-18
Lock
Washers
5/16"
Lock
Washers
5/16"
Bolts
5/16"-18x7/8"
Bolts
5/16"-18x7/8"
Door Bracket
Cut this end
Clevis Pin 5/16"x1-1/4"