Spanish to English Other Automotive / Cars & Trucks

This is something that should definitely be in the Proz database. I have the answer right in front of me, but am so totally lost when it comes to car mechanics, I can't find it.
Wiki explains the whole thing in Spanish. It even defines the two terms I am looking for. And there is a similar, but not parallel, English Wiki text.

I have posted árbol primario seperately in a previous question.

http://en.wikipedia.org/wiki/Transmission_(mechanics)

Conceptualmente, el funcionamiento mecánico de un cambio DSG equivale a dos trans-misiones en paralelo, cada una con un embrague que transmite el par motor a un árbol primario and de éstos a los árboles secundarios