As I wrote above, this way, when we just compare the speed of rotation in the clutch on both sides of the barricades and level them, very simple and effective. I tried it already in 2 different game engines - everything works! Concerning the calculation of resistance in force or torque. To calculate the resistance torque you need to know the traction force of all wheels. To calculate the traction, you need to know the current suspension force. This is easy if physics is implemented from scratch on the forces. But in our case on physics based on constraints, we can not calculate this accurately, only very approximately.