Automobiles are comprised of several interesting parts, all of which come together to form the car we know. A lot of research and engineering goes into determining the best parts and ratios for a car which is the reason behind their high cost. Among the various components a car has, the gearbox holds a special place and is also one of the most important components a car has. As a simple fact, the gearbox is not supposed to be put into reverse when the car is in forward motion, no matter if it is an auto box or manual. But what if we engage reverse gear at 100 Km/h? The video below by Garage 54 answers just that.
Going by the laws of Physics, a moving object can’t reverse without coming to a full stop. The same is applicable on cars and hence one should always bring the car to a full stop and then engage reverse. A poor old Toyota RAV4, however, received quite a beating in this video since it was the object of the experiment in this video where it was put to reverse multiple times at different speeds. The compact SUV has an automatic transmission which is put to test in this video.
In the first spin, the tester puts the car into reverse multiple times at different speeds to test what happens. However, the gearbox automatically judges that the car is in motion and does not engage reverse on its end, though the shifter is slotted to ‘R’. Therefore, the car simply coasts like in neutral until it comes to a full stop (or stopped using brakes) and then starts to reverse. To let you know, modern automatics are computer controlled and the shifter input is merely a suggestion that the computer takes and only shifts if conditions are correct, which is the case here.

In the next spin, the tester removes the plug for gear selector and a few other sensors so that the car uses less of its own mind and becomes more obedient. Now, when the car is slotted to reverse at different speeds, there is more drama as the gear tries to engage but fails to do so due to speed until finally, the speed is low enough for the reverse gear to be engaged. When viewed from outside, the car jumps a bit and the wheels lock up until the car starts reversing. When the same thing is tried at around 100 km/h, the car stalls immediately.
The tester is still not satisfied and frankly speaking, neither are we. On this quest of frying the gearbox, the next step is to remove the speed sensor. Doing so results in a big difference and a dramatic outcome. Now when the car is put to reverse, the wheels immediately lock up and stay in that position until the car stops. It then starts reversing just like normal. The same happens even in speeds like around 100 km/h except that the drama is even greater now and a strange smell starts coming out of the car.
Now when the tester drives the car with all sensors attached, the gearbox behaves in a very sluggish manner. The car goes only till around 50 km/h even when the throttle is pinned and acceleration is almost non-existent. The worst part is that the reverse gear stops responding completely and even when the engine is redlining, the car does not move back in reverse.
When the reverse gear is engaged, a smaller idler gear is put into motion. If the vehicle has not stopped, this idler gear will grind and in some cases, can even break the transmission apart. The same has happened in this case and we are pretty sure that the car will give out a hefty repair bill for the damage it has received.
In simpler words, NEVER EVER put the car in reverse gear when going forward and vice-versa. The results are not pleasant at all, as proved by this video.