• The new 6R140 heavy-duty TorqShift® six-speed automatic transmission is specifically designed to handle the increased torque produced by the all-new Ford-designed, Ford-engineered and Ford-built 6.7-liter Power Stroke® V-8 turbocharged diesel and also will be mated to the all-new 6.2-liter V-8 gasoline engine
• The new TorqShift transmission’s wider gear span, advanced controls that optimize the shift schedule, reduced parasitic friction losses and lower-rpm torque converter lock-up all contribute to improving fuel economy in the 2011 Ford Super Duty
• The new 6R140 transmission provides full SelectShift™ capability and is available with segment-exclusive Live Drive Power Take Off (PTO) with the new diesel engine

DALLAS, Sept. 24, 2009 – All-new diesel and gasoline engines are key reasons why the 2011 Ford F-Series Super Duty maintains best-in-class towing and payload and adds enhanced off-road capability. Managing the increased horsepower and torque is the all-new 6R140 heavy-duty TorqShift® six-speed transmission, which delivers power quickly and seamlessly while maximizing fuel economy.

“Our new transmission perfectly complements our new diesel and gasoline engines to give the customer the best powertrain for Super Duty applications,” said Al Bruck, 6R140 transmission engineering manager. “Rigorous testing ensures our transmission and powertrain is up to the challenge of even our most demanding Super Duty customers. Overall, the 6R140 heavy-duty TorqShift six-speed transmission enables greater customer capability, efficiency and control than ever before.”

Creating a transmission to serve both diesel and gasoline engines in a Super Duty application is a challenging proposition because the gearbox needs to deliver the substantial low-rpm torque produced by the diesel engine and efficiently use the higher rotational speeds of the gasoline engine. The solution was to use a proven architecture, but adapt it for heavy-duty use.

Lepelletier powerflow: New application of tried-and-true system
Ford’s 6R140 TorqShift transmission uses a Lepelletier-style powerflow, which is a proven technology in rear-wheel-drive vehicles but not typically used with larger diesel engines. A key benefit of the Lepelletier architecture is that it reduces the complexity in connecting the gearsets and clutches. The six speeds require only five clutches, and the speeds of the clutches relative to one another are low, increasing the efficiency of the system.

To handle the torque of the 6.7-liter Power Stroke V-8 turbocharged diesel, Ford strengthened the system by employing a unique powder-metal carrier in the compound Ravigneaux planetary gearset. The carrier consists of four pressed powder-metal components sinter-brazed together to form a rigid, power-dense structure. This solution ensures robustness and makes the architecture compatible with both the diesel and gasoline engines. A Ford-patented rocker one-way clutch is integrated with the carrier and helps improve 1-2 shift quality through the gearset.

“With this architecture, the new transmission can handle the enormous low-end torque produced by the new diesel engine as well as the high speeds produced by the new gas engine,” Bruck said. “The sinter-brazed gearset enables more torque capacity and greater engine speed capability.”

A deep first gear ratio and two overdrive gears create a wider ratio span. This, combined with available lower axle gear ratios and a control system that automatically selects the most efficient shift schedule, provides an outstanding combination of pulling power and fuel economy.

“Our first gear ratio is a fair amount deeper than our competitors, so customers will get improved off-the-line performance,” Bruck said. “The six ratios we’ve selected provide greater overall span and better overdrive performance, which reduces engine speed in highway conditions and improves fuel economy.”

“Because we have six gears, we make smaller steps gear to gear, which helps keep the engine in its sweet spot in terms of performance and efficiency.”

Six-speed gearbox offers best of automatic, manual transmissions....