A drive shaft disconnect for tow vehicles, also known as a drive shaft coupling, is a special mechanical device that disconnects a vehicle's drive axle from its drive shaft. Towing a rear-wheel drive vehicle by its front axle without disconnecting the drive shaft from the rear axle can cause serious, irreversible damage to the vehicle.
Drive shaft disconnects are only really necessary for rear-wheel drive vehicles towed on a regular basis. Installing a drive shaft disconnect is particularly economical for recreational vehicle owners who regularly tow their cars and trucks behind the larger vehicles. When most rear-wheel-drive vehicles break down, it is much more economical to call for a flatbed tow truck, as these trucks do not turn either of the vehicle's axles. For some vehicles, a standard tow truck can tow the vehicle by lifting its rear wheels off the ground, but this is only possible on those vehicles with sufficient front-side ground clearance.
While a mechanic can disconnect the cable that connects the drive shaft to the drive axle without using a drive shaft disconnect, this is an expensive job that is often impossible to perform in roadside tow situations. Furthermore, while having a mechanic disconnect the components is difficult and time-consuming, disconnecting the shaft from axle using a drive shaft disconnect only requires pulling a lever inside the vehicle.