The Lippert 298274 is a complete electric drum brake assembly designed for 3,500 lb trailer axles. Sized at 10 inches in diameter by 2-1/4 inches wide and mounted on the right-hand (curb) side, this assembly arrives ready to bolt on with all major components included -- no hunting down separate hardware kits. It fits a wide range of single- and tandem-axle trailers including travel trailers, fifth wheels, utility trailers, and boat trailers running 3,500 lb axles.
Many brake replacements turn into parts-sourcing projects when you discover the kit is missing the magnet, the adjusting screw, or the return springs. Lippert ships the 298274 as a full assembly -- backing plate, brake shoes, electromagnet, actuating lever, adjusting screw, and all spring hardware included. Install time is approximately 30 minutes per wheel for a technician familiar with drum brakes.
The electric actuation system works with any standard 12V brake controller. When the tow vehicle applies the brakes, the controller sends current to the electromagnet inside the drum. The magnet energizes, grips the rotating drum, and the resulting force drives the actuating lever outward to press the shoes against the drum surface -- delivering smooth, proportional stopping power without a hydraulic system.
Backing plate, shoes, magnet, actuating lever, adjusting screw, and spring hardware all included out of the box.
Configured for the right-hand (curb side) wheel. Verify position before ordering -- left-side application requires a separate assembly.
Standard four-bolt backing plate pattern fits most 3,500 lb axle flanges from Dexter, Lippert, and comparable manufacturers.
Estimated 0.5-hour installation per wheel. Designed for straightforward bolt-on replacement with basic hand tools.
Electric drum brakes use an electromagnet mounted to the brake shoe assembly. When the brake controller in the tow vehicle sends a 12V signal, the electromagnet energizes and is attracted to the inner face of the spinning brake drum. That rotational force actuates the lever arm, which spreads the shoes against the drum to create braking friction. The harder the controller signal (proportional to deceleration), the more clamping force is applied.
This system requires a compatible electric brake controller installed in the tow vehicle. The controller must be properly adjusted for trailer weight to avoid wheel lockup or insufficient braking. The 298274 is compatible with all standard 12V proportional and time-delayed brake controllers.
The 298274 is designed for 3,500 lb capacity axles equipped with a 10-inch brake drum. This brake size is among the most common in the RV and trailer industry, found on single axle trailers up to 3,500 lb GVWR and on each axle of tandem setups up to 7,000 lb combined. Axle brands commonly using this brake size and bolt pattern include Dexter (formerly known as Alko Dexter), Lippert, and similar North American axle manufacturers.
"Right hand" or "curb side" means the passenger side of the trailer when facing in the direction of travel (same side as the road curb in North America). If you need the driver-side brake, order the left-hand version. Installing a right-hand assembly on the left wheel will result in incorrect shoe geometry and unsafe brake operation.