Algodoo

Scripted Constraints II might help.

Won´t help me, i cannot respawn whole truck and trailer every time they de-/couple

To uncouple two objects connected by a hinge, just set the hinge's timeToLive = 0.

If your thinking "I cannot respawn whole truck and trailer every time they couple", then my question is: Why not? Maybe you could do it, but choose not to. You can spawn a whole scene if you want to. See Eight In One.

What's wrong with the solution you show in the scene above?

It is not wrong solution, but not what i wanted
(this coupling is already working and I made it for toni scene)
Spawning lots of object cause lag, and i´m not sure if i could respawn toni´s truck with spring engine (and with same details as engine RPM etc.) without blowing up whole scene

How about a circle that fits in a ring and you use collideSet to engage and disengage.

P.S. A circle in a triangle frame made of boxes is fairly strong and is quicker for Algodoo to calculate than a circle in a ring.