BMC Overdrive Gearbox .

BMC/British Leyland Gearbox, with Laycock Overdrive Unit giving six speeds (4+2 - Overdrive in 3rd and top). Originally fitted to an 1800D engine in a light sherpa crewbus, but should also match a B series engine or similar in other vehicles. Was in good working order and a pleasure to drive when removed - the vehicle itself died of rust not machanical failure.