A direct-replacement motor for Klauber D-300 Series electric through-frame slide-out systems. Engineered for Class A and Class C motorhomes running 2x2, 2.5x2.5, 2x3, and 3x3 square-tube frame systems -- restoring reliable, full-travel slide operation without a full mechanism overhaul.
When your electric through-frame slide-out becomes sluggish, fails to retract, or stops moving entirely, the motor is frequently the culprit. The Lippert 138449 is the factory-specified replacement motor for Klauber D-300 Series through-frame mechanisms -- the same unit Lippert and Klauber originally spec'd for these systems. Swapping the motor instead of replacing the entire mechanism saves significant time and cost.
This motor runs on 12V DC and draws up to 30 amps under load, so your RV's existing slide-out wiring and circuit breaker are already sized to handle it. The 3/4" hex or keyed drive shaft connects directly to the gearbox output shaft on D-300 series units. No adapters are needed when replacing a stock D-300 motor.
Runs directly from your RV house battery bank -- no inverter or converter required for slide operation.
Matches the OEM current spec so existing wiring, fusing, and the slide-out control board are not stressed.
Direct bolt-in fit to D-300 series gearbox output -- no shaft adapters or machining needed.
Low-speed, high-torque output designed specifically for the load and travel distance of through-frame slide systems.
Through-frame (also called "electric through-frame" or ETF) systems push the slide room in and out using a rack-and-pinion or screw-drive mechanism that passes through the main frame rails of the coach. The D-300 series is among the most widely used through-frame mechanisms in Class A gas and Class C motorhomes built from the mid-1990s through the mid-2010s.
The motor mounts directly to the gearbox assembly and is the primary wear item in the mechanism. Bearings, brushes, and armature windings degrade over years of seasonal cycling, especially in coaches that sit for extended periods with moisture in the motor housing.
Part number 138449 is the Lippert/Klauber catalog number for the D-300 Series motor. If your existing motor has this number stamped on its housing or listed in your coach's parts manual, this unit is a confirmed direct swap. No wiring modifications are required.
The D-300 motor drives gearboxes used across multiple tube sizes in the through-frame family. Confirmed compatible frame configurations include:
If you are unsure which tube size your coach uses, measure the square slide-out drive tubes visible inside the slide-out bay. The motor itself is the same unit across all four configurations -- the gearbox housing changes but the motor interface does not.
Klauber D-300 through-frame systems were factory-installed by chassis and coach builders including Fleetwood, Coachmen, Holiday Rambler, Winnebago, and others during the peak of through-frame adoption. Check your coach's original build sheet or the slide-out mechanism label for "Klauber" or "D-300" to confirm fitment before ordering.
Motor replacement on a D-300 system is a manageable DIY job for an owner comfortable with basic 12V electrical work and hand tools. General steps include:
Before ordering a replacement motor, confirm the motor is the actual failed component. Slide-out issues are also caused by failed limit switches, a faulty control board, broken rack teeth, or low battery voltage. A motor that runs freely when disconnected from the gearbox but stalls under load may indicate a mechanical bind in the rack or gearbox -- not a motor failure.