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 adjustment 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 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.

•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

Inner Trolley

Outer Trolley

Figure 5

Door		Ring
Bracket		Fastener	Nuts
		Lock	Nuts
		Lock	5/16"-18
		Washers
Clevis Pin	Straight	5/16"
Clevis Pin	Straight
5/16"x1-1/4"	Arm
	Bolts		Curved
	5/16"-18x7/8		Curved
	5/16"-18x7/8		Door Arm
			Door Arm
	CORRECT	INCORRECT
	Straight	Straight
	Door Arm	Door Arm

	Curved	Curved
	Door
(Groove		Door
	Arm
		Arm
facing out)

-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 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.

Door Arm

Connector Hole

Door Arm

Closed

Door

Emergency Release Handle

Outer Trolley

Inner Trolley

Correct Angle

Door Arm

Open Door	Door with
	Backward Slant (Incorrect)

3255M 1/2 HP, 3245M 1/3 HP, 3255-2M 1/2 HP specifications

The Chamberlain 3255-2M, 3245M, and 3255M garage door openers stand out in the market for their reliability and superior performance. Each model offers a unique combination of power and features, catering to different needs and preferences.

The Chamberlain 3255-2M is a robust 1/2 HP opener designed for heavy residential garage doors. Its powerful motor ensures smooth and efficient operation, making it ideal for doors weighing up to 7 feet high. This model incorporates the latest in opening technology, including a durable chain drive mechanism that provides strength and longevity. One of its significant features is the incorporated MyQ technology, enabling users to control their garage door remotely through a smartphone app. This innovative feature brings convenience and peace of mind, as homeowners can check the status of the door from anywhere.

Another excellent choice is the Chamberlain 3245M, a 1/3 HP model that offers a balance of performance and affordability. It is suitable for lighter doors, providing consistent and reliable opening and closing. The 3245M model also boasts a protective cover that enhances its durability against the elements. It operates quietly thanks to its direct drive system, making it an excellent option for garages attached to living spaces. Like the 3255-2M, this model is also equipped with MyQ technology, allowing users to monitor and control their garage door from their smartphones seamlessly.

Finally, the Chamberlain 3255M, another 1/2 HP opener, offers similar features to the 3255-2M but with a focus on belt drive technology. This model is built for quieter performance, making it ideal for homes where noise is a concern. The belt drive reduces vibrations and sound, ensuring a smoother user experience. This model also comes with a battery backup system, which provides added security during power outages.

All these models emphasize safety and security, featuring auto-reverse functionality that senses obstacles and prevents the door from closing on them. The Chamberlain garage door openers are also equipped with a rolling code technology that changes the access code each time the remote is used, enhancing security against unauthorized access.

In summary, the Chamberlain 3255-2M, 3245M, and 3255M garage door openers cater to a variety of needs with their powerful motors, innovative technologies, and user-friendly features. Their reliability and performance make them an excellent investment for any homeowner.

Chamberlain 3245M 1/3 HP, 3255-2M 1/2 HP ALL ONE-PIECE Doors, Assemble the door arm, Figure

Models: 3255M 1/2 HP 3245M 1/3 HP 3255-2M 1/2 HP