Press Release
Unique AWD system joins new Ford Transit line-up
- Ford introduces intelligent All Wheel Drive system to the new Transit line-up
- Available on single rear wheel, rear wheel drive Transit with 2.4 litre Duratorq TDCi diesel engine with 103kw (140PS) and six speed manual transmission
- All Wheel Drive system increases traction capabilities without affecting road performance or ground clearance
- Unique system features water-free hydraulic freewheel clutch mechanism and intelligent variable torque flow to the front wheels
- Ideal for utility companies, hotels, ski resorts, police forces, forest wardens
- New Transit All Wheel Drive premieres at 2006 Hanover Commercial Vehicle Show
Ford now broadens the acclaimed Transit line-up with a new All Wheel Drive (AWD) option. The AWD system is purely mechanical and automatically provides stepless torque flow to the front wheels when required on slippery surfaces.
This new option is specifically targeted at customers who frequently face low friction surfaces, adding more flexibility and reliability to their transportation needs. The new derivative will make its public debut in September at this year's Commercial Vehicle Show in Hanover, Germany.
Just recently introduced, the Ford Transit range showcases what versatility for commercial vehicles is all about – a range of clean and efficient engines, a choice of front or rear drive wheel drive, dozens of body configurations, a heavy duty front axle option, and passenger car comfort.
The Transit's AWD system is available with the 2.4-litre Duratorq TDCi diesel engine with 103 kW (140PS) and a six-speed manual transmission.
This is how the system works: Encapsulated layshaft transmission housings transfer the drive off the transmission main shaft via a helical gear set towards the front axle. A short straight axle under the transmission clutch housing carries one mechanical multiplate clutch on each end with the hydraulic freewheel mechanism with all valves incorporated into each of the clutch housings.
The AWD system is purely mechanical and self-activated, which means the driver is not distracted by having to engage the system and can therefore fully concentrate on driving. Furthermore, the system dramatically increases traction capabilities and positively affects the vehicle's road performance as a safety plus.
"The Transit AWD system gives the driver a lot of extra confidence when driving over slippery road surfaces", says David Gregory, Chief Programme Engineer. "Also, the system's smart design helps to reduce friction and mechanical losses compared to other AWD technology."
Ford Transit's key attributes are not sacrificed. Because of the smooth and intelligently controlled torque flow to the front wheels via intelligent freewheeling hydraulic control, the Transit's well proven driving dynamics are fully maintained under all conditions. Also, standard ground clearance is fully retained as a bulky differential housing architecture at the front axle simply is not needed for this compact and lightweight AWD system.
Compared to standard rear wheel drive Transit, the additional front axle weight due to the integrated helical Z-drive of the AWD system is only approximately 50 kilos – the rear axle weight does not change.
The Ford Transit AWD will be offered with rear wheel drive, single rear wheel vehicles across a broad range of cab-styles including single and double chassis cab, M2 Bus, Kombi and Kombi Van, and the standard Transit van range including double cab in van. Low, medium or high roof derivatives will be available and short, medium or long wheel base.
Europe-wide sales will start in early 2007.
Key customers for the new model are those frequently encountering low friction surfaces and bad weather conditions. Transit AWD has outstanding off road capability but does not include raised ground clearance, therefore retaining standard load heights. As such, the Transit AWD will be an ideal shuttle vehicle for ski resorts and hotels in mountainous areas where drivers encounter snow and icy conditions which lead to reduced grip.
The new Transit AWD is also perfectly suited for authorities like police, forest wardens, rescue services and fire departments, providing the reassurance and confidence to handle situations which are beyond the capabilities of a standard vehicle. Transit ambulances fitted with the AWD system will be able to ensure ongoing mobility in adverse conditions and deliver patients safely where previously they may have been halted by a low friction surface.
Utility companies will also benefit from the capabilities of the Transit AWD, as they will be surefooted performers for field and track work (for example crossing a muddy field track to fix a pylon) without the need to send two vehicles in case the first becomes stuck on a slippery surface. Ultimately this saves time and means that utility resources can be more effectively deployed.
"The all-wheel drive system is completely transparent to customers, requiring no driver intervention, and it doesn't sacrifice any of the vehicle's core commercial qualities. It greatly expands Transit's capability as it adds more safety and flexibility to any kind of delivery or transport usage and really enhances the line-up", adds Gregory.
Functional overview: Ford's Intelligent Transit All Wheel Drive system
Under normal driving conditions, the Ford Transit AWD only uses rear wheel drive. However, should road surfaces become slippery with rain, snow, ice or split friction, a loss of traction might occur and the rear wheels are likely to slip. Ford's mechanical torque sensor will automatically engage the two clutches inside the front transmission, which at the same time limits the rear axle's overspeed and transfers torque towards both front wheels for additional traction. At the same time the de-stabilising effect of spinning rear wheels is being re-balanced from oversteering to a neutral driving behaviour by the physical torque flow to the front wheels.
A core element of the system is a hydraulically controlled torque sensor inside the front axle transmission. By sensing speed difference between front and rear axles, the integrated oil pump will continuously lock the multi plate clutch to one of the front wheels and gently convert torque to the front wheel.
The system is completely mechanical and free of wear – no service is required during its lifetime, apart from oil level control inside the clutch housings. Another core element of the system is an Eaton-type oil pump inside each of the clutch housings. It uses a small volume of oil to engage the clutches whenever required (transmission oil type 75W-90 BO).
As long as the front wheels rotate on dry and solid ground at the same speed as the rear wheel drive axle, both clutch pumps remain static and the entire hydraulic system is without function – the clutch locking system remains without pressure and both clutches are open. In case of minor speed differences typical for cornering situations, the pumps begin to rotate gently and pump a small amount of oil through the valves of the clutch system, without closing them for straight torque transmission.
As soon as the rear wheel drive shows significant slip, both clutches inside the system engage as the inner rotor and outer rotor begin to rotate at different speeds. At an appropriate speed difference the two hydraulic valve systems close the clutch system to each front wheel, delivering enough torque to either wheel to stabilize the drive situation and reduce overspeed effects at the rear axle.
Once all wheel speeds are adjusted to a close to identical level, the system disengages automatically by releasing oil pressure from the clutch system. In order to adjust the clutch system to different oil temperatures – which may vary from -40 °C to around 100 °C – a viscosity compensation valve is embedded into the system.
"We're delighted to be able to offer this unique AWD system to Transit customers as a manufacturer option," concludes Joe Bakaj, vice president, product development, Ford of Europe. "Transit AWD demonstrates how committed Ford is to keeping the Transit range at the forefront of the medium commercial vehicle market in Europe, as well as responding to specific customer wants in this highly competitive marketplace."
