- May 8, 2008
Ford begins production of new mid-range six-speed automatic
For 2009, the Ford Escape and Mercury Mariner (as well as the Mazda Tribute) are getting the powertrain updates that they missed out on when their exteriors were revamped last year. While the 2008 models had all-new looks and interiors, the engines and transmissions were carried over from 2007, including the four-speed automatic transmissions. We'll have more info on their new 2.5L four-cylinder and 3.0L V6 engines after we drive them next week, but Ford released some information on their new six-speed transmissions when we visited its Van Dyke Transmission Plant in Sterling Heights, MI.
The new 6F35 is a completely new six-speed automatic that will have a wider total ratio spread than the four speed it is replacing. The top gear ratio will be approximately the same as the four-speed, but the lower gears will be shorter helping off-the-line acceleration. The final drive ratio will be a little taller (numerically lower), which will help reduce the engine speed when cruising on the highway. Even with the larger first to sixth spread, the overall gap between each ratio will be smaller resulting in less engine speed drop during shifts and a quieter, smoother overall driving experience. The 6F35 uses a total of three planetary gear sets and five clutches to generate the six forward and one reverse gear.
Ford is claiming that the new transmission contributes to a 4-6 of all its automatics to be 6-ratio variants.
FORD'S NEW 6-SPEED AUTOMATIC TRANSMISSION OFFERS 4-6 PERCENT FUEL ECONOMY IMPROVEMENT
- The new 6F35 front-wheel-drive transmission is the latest example of Ford's powertrain technology that increases fuel economy and lowers CO2 emissions.
- The new 6-speed debuts in the 2009 Ford Escape and Mercury Mariner sport-utility crossover vehicles.
- Advanced automatic transmissions represent one part of Ford's comprehensive strategy to improve fuel economy and deliver sustainable solutions for customers.
The new 6F35 front-wheel-drive transmission offers a 4 to 6 percent improvement in fuel economy versus conventional 4- and 5-speed automatics, in addition to improved acceleration.
"With a greater gear span, the 6F35 allows the engine to operate at more optimum combinations of speed and load to meet certain driving conditions," said Craig Renneker, chief engineer for new automatic transmissions, Ford Powertrain Operations. "The new transmission also enables the engine to run at lower speeds on the highway, which aids fuel economy."
The 6F35 will be mated to a new 2.5L I-4 engine and a power-improved 3.0L V-6 in the 2009 Escape and Mariner. The engine offers horsepower increases of 17hp for the I-4 and by 40hp for the V-6, while also boosting fuel economy by 1 mpg when mated to the new six-speed transmission. The 2009 Mazda Tribute also will feature the 6F35, as will two other vehicles early next year.
The new 6-speed offers numerous technologies and design features that increase durability, performance and quietness. Ford's patented one-way rocker clutches allow for smoother, quieter, more precise shifts. Working like a socket wrench, the rocker clutches spin freely one way, but securely lock in the other direction. As result, gears are engaged and disengaged more quickly.
Other notable features include:
- Chain-driven secondary gearset – Specifically designed with random-size links, the unique chain reduces noise, vibration and harshness when driving the transmission's secondary gearset.
- Unique pump-filter interface – Virtually eliminates pump whine, contributing to projected best-in-class noise, vibration and harshness characteristics.
- Flat-tow capability – Vehicles equipped with the 6F35 can be flat towed (all four wheels on the road) behind other vehicles without damaging the transmission. When flat towed, the transmission is in neutral, but internal parts rotate, causing heat. With the engine turned off during towing, the pump cannot create pressure to move oil around in the transmission and cool parts. To address this, internal baffling was added to the 6F35 to capture and direct oil to key areas.
- Fluid fill for life – A special blend of transmission fluid is maintenance free for the life of the gearbox.
- Transmission System Characterization – A process that utilizes software to ensure proper transmission operation before a vehicle leaves the assembly plant. During final testing, the functioning of several common shift cycles are matched against established parameters. Variability is then corrected by software in the Powertrain Control Module. The process helps deliver a high-quality, correctly operating transmission to customers from the very first day they drive their new vehicle.
Ford automatic transmissions are subjected to hundreds of hours of durability, noise, vibration and harshness (NVH) testing. A series of accelerated durability trials equate to 150,000 miles of the most abusive customer usage under extreme conditions.
"One test for the 2009 Escape was to run in fourth gear with maximum trailer load at 100 mph for 15 miles. And that was repeated about 500 times," explained Rich Rej, 6F35 systems engineer, Ford Powertrain Operations. "We determine what the most abusive driver would do to our transmissions and then we do more to it to make sure that we are delivering a high-quality, durable gearbox for our customers."
Ford also utilizes a state-of-the-art Transmission NVH Hemi Anechoic Chamber that allows engineers to develop hardware to meet noise and vibration targets that will result in a quiet, interior cabin, and yield higher customer satisfaction levels for transmission quietness.
The new 6F35 6-speed automatic transmission is assembled at Ford's Van Dyke Transmission Plant, which also produces the 6F50 6-speed automatic in 2008 models of the Ford Taurus, Taurus X, Edge, Mercury Sable, Lincoln MKX and 2009 Ford Flex and Lincoln MKS.
Ford 6F35 front-wheel-drive, 6-speed automatic transmission:
Van Dyke Transmission Plant (Sterling Heights, Mich.)
Sharonville Transmission Plant (Sharonville, Ohio)
2009 Ford Escape
2009 Mercury Mariner
2009 Mazda Tribute