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Adapting an automatic transmission vehicle for towing four wheels down

Certain automatic-transmission vehicles that are are not manufacturer-approved for towing four wheels down can be towed safely with the addition of aftermarket equipment.

Contact the manufacturer of the aftermarket equipment for details about the towability of a specific vehicle.

Drive-shaft coupling
For rear-wheel-drive vehicles with automatic transmissions. Consists of a mechanical clutch that can be engaged and disengaged from the driver's seat of the towed vehicle via a remote cable. This is accomplished by reworking the towed vehicle's drive shaft or purchasing a new drive shaft that already has been reworked (which would allow you to keep the original drive shaft for reinstallation at trade-in time). With drive-shaft coupling, odometer miles are not logged on the towed vehicle while it is in tow. 

Transmission fluid pump
Primarily for front-wheel-drive vehicles with automatic transmissions; limited applications for rear-wheel-drive vehicles. Check with the transmission lube pump manufacturer first. Modern automatic transmissions are equipped with only an engine-driven front lubrication pump. When the towed vehicle is not running, the transmission pump is not pumping. Thus, an alternate lubrication source is necessary.

The lube pump components are installed in the engine compartment of the towed vehicle. The pump is powered by the motorhome and usually controlled by an electronic monitor mounted on or near its dashboard. Fluid is pumped through the transmission cooler in the radiator and then into the transmission lubrication system. Some lube pump manufacturers warranty not only the lube pump system, but also the towed vehicle's transmission.

One factor to consider when deciding between these two systems is future vehicle purchases. The initial cost of the drive-shaft coupling is lower than that of the lube pump, but the drive-shaft coupling is designed for use with a specific-make rear-wheel-drive vehicle. Unless your next car is the exact same make and model, you may lose your investment. The lube pump, on the other hand, is universal to many front-wheel-drive vehicles and can be transferred intact from one vehicle to another.

Axle-Lock
Available from Remco, for front-wheel-drive vehicles with automatic transmissions. The Axle-Lock is a device that is installed on the axle shaft, or half shaft, of the front-wheel-drive vehicle. Utilizing four-wheel-drive hub technology, the half shaft is engaged and disengaged with a twist of the Axle-Lock. The axle lock is permanently installed and is vehicle specific. Because of space problems under or around the front axle, an axle lock will not fit some vehicles.