What is the reason why AWD (All-Wheel Drive) cannot be towed?
3 Answers
The specific reasons why AWD (All-Wheel Drive) cannot be towed are as follows: 1. The engine's power output is connected to both the front and rear axles through the drive shaft. 2. In principle, the engine, drive shaft, and all four wheels operate simultaneously. 3. If the vehicle is towed, the friction force borne by the rear wheels directly affects the tires, causing damage, while the drive shaft also undergoes deformation force, leading to certain damage. An introduction to AWD (All-Wheel Drive) is as follows: 1. AWD does not require driver intervention. Once poor road conditions or wheel slippage are detected, the system automatically adjusts the engine's torque distribution to the front two wheels, naturally switching to four-wheel drive mode, making it simpler to use. 2. AWD automatically engages four-wheel drive only when the vehicle encounters conditions that require it, otherwise, it operates in two-wheel drive mode. 3. Compared to other four-wheel-drive systems, AWD has a simpler structure, effectively reducing costs and overall vehicle weight.
I've read a lot of information online and consulted with my mechanic friends. The main reason why part-time 4WD vehicles can't be towed is because their drivetrain is too sophisticated. During towing, the wheels are forced to rotate, but the center differential or coupling in part-time 4WD systems can't slide freely. When there's significant wheel speed difference, internal components can get stuck and overheat, potentially damaging bearings and gears at minimum, or burning out the entire system at worst. This is no joke - when I first bought my car, I almost made this mistake when a friend tried to tow my vehicle. Fortunately, I stopped them in time before any towing occurred. Now I know you must either flat tow or lift the drive wheels off the ground. The electronic control unit might also misjudge road conditions and cause malfunctions. Regular maintenance is crucial - don't wait until problems occur to get repairs.
As someone who frequently repairs these types of vehicles, I must say towing a part-time 4WD vehicle is absolutely not advisable, and the reason lies in its mechanical structure. The center differential is the core component, designed to flexibly distribute power. However, if the vehicle is towed with wheels turning, the inconsistent rotation speeds between the front and rear wheels can cause the coupling to overheat and lock up, damaging the internal oil seals and gears. Electronic sensors would also go haywire, mistakenly engaging the 4WD system and potentially causing short circuits in the electronic systems. The repairs are a nightmare—just one improper tow could cost the owner tens of thousands to replace the entire set of components. That's why I always remind people not to attempt towing these vehicles; using a flatbed tow truck is the safest option.