LiftMaster LA400DC Primary 24V DC Swing Gate Actuator Arm

The LiftMaster LA400DC is the primary 24V DC actuator arm used in compatible LiftMaster LA400 swing-gate systems. It moves the gate leaf through the system’s approved bracket arrangement and connects to a compatible control box. This is the primary-arm reference, distinct from the LA400DCS secondary arm and the LA400PKGUL system package. It is suited to a replacement purchase only after the arm, controls, mounting geometry and gate condition have been checked together; system accessories and exact carton contents must be confirmed separately.

Compatibility — Models, Versions and Exclusions

What the Installer Should Evaluate Before Replacing an Arm

The gate leaf, hinges, posts and brackets are part of the operating system. A binding gate or damaged support can put an otherwise correct actuator under abnormal load. Replacing the arm without correcting the mechanical cause may leave poor operation unresolved. Provide the gate dimensions and clear views of the existing mounting arrangement along with the model labels.

For a new installation, the arm is only one purchasing decision. The control system, power arrangement, brackets, access controls and protection devices must form an approved combination. For a replacement, confirm which existing components can be retained. Exact cable and bracket contents for this supplier offer need confirmation; do not use a system-package photograph as proof that those items come with the arm.

Arm or Complete Package?

LA400DC identifies the primary actuator arm. LiftMaster uses LA400PKGUL for a single-arm system package and LA400DCS for the secondary actuator in a dual-gate arrangement. Confirm the exact package when ordering a new system or replacing an existing arm.

Specifications

Capacity Depends on Gate Length

LiftMaster’s LA400PKGUL product guide pairs the LA400DC arm with recommended gate capacities of 850 lb at 10 ft, 750 lb at 12 ft, 650 lb at 14 ft and 550 lb at 16 ft. These are length-and-weight combinations, not a claim that a 16-foot gate can weigh 850 pounds. Confirm the current system manual and complete installation conditions before selection.

Replacement Checklist

• Match the actuator and control-box model labels.
• Check the gate length, weight and condition.
• Confirm bracket geometry and the intended opening direction.
• Verify the arm connection and the manufacturer-approved control system.

Frequently Asked Questions

Can I use this as the secondary arm on a double gate?

LiftMaster specifies LA400DCS as the secondary arm. Confirm the required primary or secondary position before ordering.

Does the arm alone provide smartphone control or battery backup?

Those functions depend on the complete compatible control system, power arrangement and accessories. An arm-only purchase does not establish those features.

Safety Warnings — Read Before Installation or Service

• WARNING: Moving swing gates can trap or crush people and cause serious injury or death. Installation and service require a trained gate-systems technician.
• This actuator is for an approved vehicular gate system. Provide pedestrian access separately; do not use the moving vehicle gate as a pedestrian entrance.
• Secure the gate leaf and isolate all power before disconnecting the arm. Gate weight and free movement must remain controlled during service.
• Protect identified entrapment zones. Do not bypass monitored sensors or increase force to overcome a binding gate. Complete setup and safety tests before use.

Related Products and Important Differences

• K001A6039 LA400 control board — an older control reference to compare when identifying the installed system; it is not automatically the correct board for every LA400DC arm.
• LMWEKITU monitored wireless edge kit — a way to connect compatible resistive edges on approved systems. The kit is separate from the actuator and requires edge sensors.
• LMRRUL monitored photo eye — a separate non-contact protection option when listed by the exact operator manual; placement depends on the site’s entrapment zones.

More Questions Before Ordering

Can an arm replacement fix a sagging or binding gate?

No. Structural and hinge problems must be corrected first. An actuator should move a mechanically suitable gate, not compensate for damaged supports.

How do I confirm what comes in this arm shipment?

Ask for the current LA400DC supplier carton contents, including cable and bracket details. The LA400PKGUL system-package inventory should not be applied to this separate SKU.

Need Help Confirming the Right Part?

Contact Garage-DoorParts.com before ordering. Send the full operator model, readable part labels and photographs of the installed assembly. Include dimensions or the control-box model where relevant. We can help compare the listing with the information you provide; final installation suitability should be confirmed by the servicing technician.