Test drive Land Rover Defender VDS Automatik: stepless Landy

Especially suitable for off-road diesel vehicles.

A new automatic transmission is being produced in Austria, especially for SUVs. The first test car was the Land Rover Defender.

Anyone who frequently drives in difficult terrain knows the benefits of an automatic transmission. Constant traction, optimal gearing depending on the situation, no mechanical clutch as a possible source of failure and, last but not least, of course, higher driving comfort. In the SUV sector, a transmission with a classic torque converter is almost always available. A continuously variable transmission is too small compared to, for example, a modern dual-clutch automatic transmission and is not suitable for high off-road loads. The Austrians are stepping on a new footing: with a continuously variable planetary transmission to be used in the SUV sector. The Land Rover Defender is the test vehicle of VDS Getriebe Ltd's new transmission concept.

Defender with stepless automation

As an all-terrain vehicle, the Defender provides the perfect base to showcase the benefits of a continuously variable automatic transmission. The Variable Twin Planet, or VTP for that name, is what the R&D engineers called the gearbox, while at the same time giving the appropriate description of the action: the double planetary gear at the gearbox output is the heart of the new transmission. VTP transmission operates as a so-called power branch transmission. This means that an additional hydrostatic part is installed next to the planetary gear, which at low speeds takes over the drive of the wheels through the oil pump and the hydraulic motor driven by it. A design with a similar function is available in Toyota hybrid vehicles, but is actually for a different purpose and is electrical rather than hydraulic.

VDS originally developed VTP gears for agricultural machines, and these gears have been standard for tractors for some time. Compared to truck transmissions, the Land Rover Defender test transmission is downsized and the benefits of this technology are being used for the first time on an SUV.

The best of both worlds

Of particular importance to off-road riders, the VTP transmission completely eliminates the biggest drawback of a conventional torque converter - reduced engine braking on steep descents. Due to the permanent connection between the engine and transmission, full engine braking can be applied until the final stop. The VTP gear provides a strong start without interruption in traction, even at low engine speeds. CVT also eliminated the distribution system for the off-road transmission - (in the test car this is achieved via buttons on the center console), there is a choice of only forward and reverse speed, there is also an integrated differential lock system for a rigid connection between the two axles. Cruise control is further integrated into the VTP transmission.

VTP transmissions for SUVs are currently still in test mode, Defender is the first test car. Of course, there is no information about possible prices and serial production yet. The gearbox is designed for an input torque of up to 450 Nm and a speed of up to 3600 rpm, so it is mainly suitable for diesel SUVs.

2020-08-30