FWD sequential gearboxes SD905 5 speed front wheel drive transmission. Different versions of the SD90 gearbox fit very different cars. Many competitive FWD cars now rely on the superior reliability of the SD90 gearbox. SD906 6 speed front wheel drive transmission. Different versions of the SD90 gearbox fit very different cars. Many competitive FWD cars now rely on the superior reliability of the SD90 gearbox.