In the long run it can cause damages. Change it to the correct fluids. a.s.a.p.
The transmission will fail.
not sure about how you tell if something is wrong, but i can tell you without fluid in your transmission for any period of time can very possibly destroy it.
The car will not move when you put it in gear.
Yes it can and will. Using the wrong transmission fluid for your vehicle will most likely blow your seals. If you put a heavier fluid than required it can break the aluminum flaps that control fluid movement.
Its going to tear up the engine
at first, nothing. then approx 1000 miles later, the transmission will actually explode. depending on the type of vehicle/transmission, the explosion could very well injure you.
it's ok
what can happen to the transmission? Also is it possible to put fluid back in to save the transmission? You won't get far and you will probably do some damage to the transmission in the process.
If any fluid except for the correct transmission fluid is put into the transmission of a car, it will eventually fail. If this happens, a person must flush the transmission of the car.
Similar products should not be a problem
You will get streaks and blotches on your windscreen.
it will free a stuck valve