Towing a vehicle from the back, often referred to as flat towing or dinghy towing, is a common practice for recreational vehicle owners and those needing to transport a disabled car. However, the simple answer of yes or no is insufficient because the procedure is heavily dependent on the specific mechanics of the vehicle being towed. Not every car is designed to have its driveshaft disconnected, and improperly executing this move can result in significant mechanical damage.
Understanding How Towing Works
To determine if you can tow a car from the back, you must first understand the basic mechanics of how a tow dolly or trailer interacts with the vehicle. When a car is being pulled by another vehicle, the transmission is usually the primary component being stressed. In automatic transmission vehicles, the output shaft is connected to the wheels; if the wheels roll and the transmission is not disengaged, the pump inside the transmission can overheat and fail. This is the core reason why simply hooking up a bumper and pulling is generally a bad idea.
The Role of the Driveshaft
The driveshaft is the critical component that transfers rotational power from the transmission to the wheels. When towing a car from the back with the driveshaft connected, the wheels are turning the transmission, which in turn tries to turn the engine. This creates a condition known as "windmilling," which places immense stress on the transmission fluid, the torque converter, and various internal bearings. Without proper preparation, this friction can destroy the transmission within a short distance.
Methods to Safely Tow from the Back
There are several established methods to mitigate the risks associated with towing a car from the rear. The goal is to ensure the transmission is not connected to the wheels, thereby preventing the mechanical stress outlined above. Choosing the correct method depends on the vehicle's drivetrain—whether it is front-wheel drive, rear-wheel drive, or all-wheel drive.
Using a Tow Dolly
A tow dolly is a two-wheeled trailer that lifts the front wheels of the vehicle off the ground. This is generally the safest and most common method for towing front-wheel-drive cars. By lifting the front tires, the dolly ensures that the transmission is not engaged with the road, eliminating the risk of windmilling. It is crucial to secure the vehicle tightly on the dolly and to ensure the tires are properly inflated to the manufacturer's specifications to prevent blowouts during transport.
Flat Towing Considerations
Flat towing, where all four wheels remain on the ground, is often popular for recreational vehicles like motorhomes towing a dinghy vehicle. However, this is not as simple as just letting the car down. Only specific vehicles are designed to be flat towed, and this usually requires the installation of a base plate or the bypassing of the internal transmission pump. Consulting the owner's manual is the only way to confirm if a vehicle is compatible with this method, as towing an incompatible vehicle will void warranties and cause immediate damage.
