How Ferguson came up with the surefooted Stag
The transition of the Stag from rear-wheel drive to allwheel drive technology was very involved. Ferguson’s engineers had to be remove the drivetrain in order to add the transfer drive casing with its twin propshafts feeding front and rear differentials, the viscous coupling device and anti-skid sensor. The front differential was bolted to the engine block with driveshaft housings attached. The driveshafts were bolted to modified Stag hub carriers machined to allow the GKN constant velocity joints to pass through to Triumph 1500 CV joints with custom-made hubs. The Stag’s MacPherson uprights were shortened, locating with Hillman Huntersourced ball race tops, and the upright studs locating with re-drilled holes in the inner wing panels.
New engine mountings were fabricated to raise the engine by 0.9in, which, in turn, meant adapting the bonnet with a dummy air scoop to clear the air filter. Meanwhile, the transmission tunnel was modified to take the transfer drive casing sitting on a Ford Escort automatic gearbox mounting and propshaft connecting with the front differential. This also meant modifying the structure of the front passenger’s seat.
The steering rack was moved and mounted on a newly fabricated subframe along with smaller items like the starter motor solenoid. Above the cooling system overflow bottle is the mighty anti-skid air reservoir.
A quick scan of FFD’s Stag build sheets reveals the complexity of the task; a different brake servo and master cylinder were fitted and the exhaust system adapted. Incredibly, records show that it took just a week of concentrated work to complete the whole conversion, reflecting the experience gained by the FFD team in undertaking similar projects on other vehicles.