Ford four-wheel drive

To add drive to the front wheels of the rear-wheel-drive Sierra and Granada Scorpio, power is taken from the side of the gearbox by a wide transfer chain after running through an epicyclic centre differential and viscous coupling.

A short prop shaft runs forward to the front differential, which is mounted on the right-hand side of the sump. The only way to get power to the left-hand front wheel is to run a drive shaft through the sump itself inside a sealed tube.