Chamberlain 3245M 1/3 HP User Manual

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.

    -  Turn the UP limit adjustment screw counter-

clockwise 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 floor), 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.

    -  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.

Nuts
5/16"-18

Lock
Washers
5/16"

Ring
Fastener

Straight
Arm

Bolts
5/16"-18x7/8

Door
Bracket

Clevis Pin
5/16"x1-1/4"

Curved
Door Arm

Door Arm

Door Arm
Connector Hole

Closed
Door

Outer Trolley

Emergency Release Handle

Inner Trolley

Outer Trolley

Open Door

Door Arm

Correct Angle

Door with
Backward Slant (Incorrect)

Inner Trolley

Straight 
Door Arm

Curved 
Door 
Arm

(Groove 
facing out)

Straight 
Door Arm

Curved 
Door 
Arm

    -  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 floor.

NOTE: When setting the up limit on the following page, the