* constant mesh helical gears -- looks fine.
* árboles dispuestos en cascada -- these can't all be "drive shafts" (simlpy say "shafts"), and I can't quite imaging that "cascade" means. Have you got a picture?
* semi-synchronized is puzzling not only to myself:
http://www.ytmag.com/case/messages/96645.htmlI notice that Bobcat boasts about their SST, but I have not seen any diagrams floating around, so don't know what that means. I think you can copy the word without knowing what it means.
* 3 palancas - levers: maybe, but I would check to make sure they are not shift rods (
http://2.ly/cjtu) -- because it would be crazy to operate a gearbox with three sticks.