All one-piece doors – Chamberlain SECURITY+ 3265M-267 1/2 HP User Manual
Page 22

22
ALL ONE-PIECE DOORS
1. Assemble the door arm, Figure 5:
IMPORTANT: The groove on the straight door arm MUST 
face away from the curved door arm (Figure 5).
• Fasten the straight and curved door arm sections
together to the longest possible length (with a 2 or 3 
hole overlap).
• With the door closed, connect the straight door arm
section to the door bracket with the 5/16"x1-1/4" clevis 
pin.
• Secure with a ring fastener.
2. Adjustment procedures, Figure 6:
• On one-piece doors, before connecting the door arm
to the trolley, the travel limits must be adjusted. Limit 
adjust ment screws are located on the left side panel 
as shown on page 23. Follow adjustment procedures 
below.
• Open door adjustment: decrease UP travel limit
- Turn the UP limit adjustment screw counterclockwise
4 turns.
- Press the Door Control push button. The trolley will
travel to the fully open position.
- Manually raise the door to the open position (parallel
to the fl oor), and lift the door arm to the trolley. The 
arm should touch the trolley just in back of the door 
arm connector hole. Refer to the fully open trolley/
door arm positions in the illustration. If the arm does 
not extend far enough, adjust the limit further. One 
full turn equals 2" (5 cm) of trolley travel.
• Closed door adjustment: decrease DOWN travel limit
- Turn the DOWN limit adjustment screw clockwise
4 complete turns.
- Press the Door Control push button. The trolley will
travel to the fully closed position.
Figure 5
Figure 6
- Manually close the door and lift the door arm to the
trolley. The arm should touch the trolley just ahead of 
the door arm connector hole. Refer to the fully closed 
trolley/door arm positions in the illustration. If the arm 
is behind the connector hole, adjust the limit further. 
One full turn equals 2" (5 cm) of trolley travel.
3. Connect the door arm to the trolley:
• Close the door and join the curved arm to the
connector hole in the trolley with the remaining clevis 
pin. It may be necessary to lift the door slightly to 
make the connection.
• Secure with a ring fastener.
• Run the opener through a complete travel cycle. If the
door has a slight "backward" slant in full open position 
as shown in the illustration, decrease the UP limit until 
the door is parallel to the fl oor.
NOTE: When setting the up limit on the following page, the 
door should not have a "backward" slant when fully open 
as illustrated below. A slight backward slant will cause 
unnecessary bucking and/or jerking operation as the door 
is being opened or closed from the fully open position. 
Straight 
Door Arm
Straight 
Door Arm
Curved 
Door 
Arm
Curved 
Door 
Arm
(Groove 
facing out)
CORRECT
INCORRECT
Door Arm
Door Arm 
Connector Hole
Door Arm
Inner Trolley
Inner Trolley
Outer Trolley
Outer Trolley
Emergency 
 Release Handle
Closed
Door
Open Door
Correct Angle
Door with
Backward Slant (Incorrect)
Door
Bracket
Straight
Arm
Bolts
5/16"-18x7/8
Curved
Door Arm
Lock
Washers
5/16"
Nuts
5/16"-18
Ring
Fastener
Clevis Pin 
5/16"x1-1/4"
