German to English Tech/Engineering Automotive / Cars & Trucks transmission in a commercial or utility vehicle

Das Kraftfahrzeuggetriebe 3 setzt sich aus einer Wendegruppe 4, einer Hauptgruppe 5 und einer Bereichsgruppe 6 zusammen, wobei die Wendegruppe 4 der Hauptgruppe 5 vorgeschaltet und die Bereichsgruppe 6 der Hauptgruppe 5 nachgeschaltet ist.

This text is from a patent, but I'm hoping that by posting it as an automotive question I'd reach more experts. I found main group for Hauptgruppe and range group for Bereichsgruppe, but can't figure out Wendegruppe. I did find electronic quick reverse, but only in the context of Mercedes Benz. I also found turn group, but I think that that is probably a machine translation. Thanks for any help.