Outwardly, the only clue to the new continuously variable transmission that features in a new range of mid-size McCormick X6 tractors is the ‘VT-Drive’ decal on the doors.
But within the transmission housing is a configuration of components that provides a driver with a choice of operating modes, plus "fine speed control and adjustment".
“This is a significant development for being the first stepless transmission developed in-house by Argo Tractors, and for the way it works,” said Ray Spinks, General Manager and Sales Director at McCormick distributor AgriArgo UK.
“But regardless of how the transmission works, the important thing is the way it provides efficient power delivery, seamless speed control and equivalent or differential speeds between forward and reverse,” he added.
“We’re confident it will make an excellent loader tractor with seamless shuttling and easy speed control, as well as a first-rate field tractor - especially for jobs and applications that benefit from the fine speed control of a CVT transmission.”
The McCormick X6 VT-Drive range comprises three models with maximum power outputs for draft work of 111hp, 121hp and 130hp. Power is boosted up to 140hp for PTO and transport applications.
In that respect, they match the existing semi-powershift models – which also use an Argo Tractors transmission – as well as the axles, engine, hydraulics and cab for "a high level of parts commonality".
The new CVT transmission has ‘road’ and ‘field’ settings - using a combination of hydrostatic and hydro-mechanical drives.
The ‘road’ setting comes with a top speed of either 40kph or 50kph, while the ‘field’ setting, which engages a reduction gear, has a maximum speed of around 30kph.
In both cases, drive is purely hydrostatic at first - before clutch-packs "seamlessly" engage to introduce a proportion of mechanical drive that increases as the tractor goes faster. A ‘hill hold’ feature prevents the tractor moving on a slope with the engine idling.
As part of the package, McCormick X6 VT-Drive tractors have a choice of mechanical or electronic spool valves – or a combination of the two – along with front axle and cab suspension, load-sensing hydraulics and a seat-mounted control console with McCormick's Data Screen Manager colour, touch-screen display.