
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% improvement in fuel efficiency depending on with which vehicle and engine it's paired. Besides the three CUVs launching shortly, the new gearboxes are also going into the revamped Ford Fusion and Mercury Milan early next year. The Van Dyke plant also builds the larger 6F50 used in the Edge, Taurus and their derivatives, as well as a smaller four-speed used in the Focus. That four-speed will also be replaced by a third smaller 6-speed in the next year or two for the Focus and Fiesta. Ford plans to double production of six-speed autoboxes by the end of 2009 to 1.4 million units and by 2012 expects 98% of all its automatics to be 6-ratio variants.
[Source: Ford]
PRESS RELEASE
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:
Assembly:
Van Dyke Transmission Plant (Sterling Heights, Mich.)
Gears:
Sharonville Transmission Plant (Sharonville, Ohio)
Products:
2009 Ford Escape
2009 Mercury Mariner
2009 Mazda Tribute













Reader Comments (Page 1 of 2)
Johnny @ May 8th 2008 4:48PM
This is good news. I like 6 speed transmissions as long as it is a true 6 speed and not a 4 with two overdrive gears.
This one seems to have 6 distinct gears so its all good.
Simon @ May 8th 2008 4:50PM
Anyone know the gear ratios from old 4 speed and new 6 speed?
Dan @ May 8th 2008 5:38PM
How are overdrives different from distinct gears?
A transmission could have 6 overdrives and no 'regular' gears at all and do just fine, so long as it was matched with a suitable axle.
EXP Jawa @ May 8th 2008 6:41PM
@ Dan
Sometimes the overdrive is simply another "regular" gearset in the transmission, like all of the other ratios, which I think is what you're thinking of.
What I think Johnny is referring to, though, is a secondary (inline) planetary gear speed multiplier that is used in combination with another "regular" gear set in the transmission. A good example of that are the overdrive units that where popular in '60s on British sports cars and such.
On an electronically controlled transmission, you can easily command it to engage the OD unit with more then one transmission ratio. Ford did that with the 5R55 family of transmissions - instead of running OD only with the 3rd gear (as in the 4R55), they operated it with 1st also, giving it "fake" second, which they could turn around and market as a 5-speed. If you combine it with 2nd as well, then you could call it a 6-speed.
Another way to do it, though, is like what Getrag did for the SVT Focus/Mini Cooper S: have 4 primary ratios and 2 final drive ratios. If you combine enough of them, you can make 6 effective gears. Maybe that's what he's thinking of...
AMcA @ May 8th 2008 9:20PM
Ford's getting its act together.
- Kirk K
jordan @ May 9th 2008 12:44AM
@StickShift
Oh AX4S/N (which ever came w/the Vulcan), how I hate thee...
MikeW @ May 9th 2008 5:54PM
http://www.ford.com/about-ford/news-announcements/press-releases/press-releases-detail/pr-ford-accelerates-shift-to-28198
{hey that is just like GM's 6t40 & 45. Primary axis, chain drive to secondary axis, and then axle ratio (helical bevel gear) to differential axis}
Look up GM's 6t45 gear ratios
http://en.wikipedia.org/wiki/GM_6T40_transmission
6t70 (no chain drive)
http://wardsauto.com/ar/ford_gm_automatic/
The dual countershaft manual transmission does not work that way.
You are not just switching axle ratios to get 6 gears, you actually have 6 gears, it just happens that 3rd/4th drive gears do double duty, driving 3/4 & 5/6.
You are not being specific enough. You should not call your transmission a 4 speed automatic, it should be called a 3 speed + overdrive.
There are wholly integral 4 speed automatics vs 3 speed + overdrive
StickShift @ May 8th 2008 5:10PM
the current Ford/GM 6 speed in the Taurus is the following. I assume the new unit should be close, if not necessarily identical ratio wise:
6F50: 4.484 2.872 1.842 1.414 1.000 0.742
The old 4 speeds varied in ratios, depending on the model, but here's one example:
AX4S 2.77 1.54 1.00 0.69
Source: http://www.vibratesoftware.com/html_help/html/Ford/Ford_Transmissions_Main.htm
Johnny @ May 8th 2008 4:56PM
I only know the old Escape ratios:
2.89 1.57 1.00 .70 and axle was 3.04
Jacob @ May 8th 2008 4:59PM
Does anyone know if this transmission is going to have some kind of manual gear select feature for driving on hilly roads, etc. I really hate it that on 500 and Fusion all you can do is select "L" which shifts down two gears, which is not necessarily what I was looking for.
MikeW @ May 9th 2008 6:12PM
Well it is Ford. They aren't designing cars for Mensa members.
Isn't there an OD off button on the side of the selector? I read the manual on the MKZ and the OD off button downshifts from 6th (or 5th) into 4th gear.
The L setting should downshift more than that.
YouFaceTheTick @ May 8th 2008 5:11PM
Why not space 6th into a real freeway gear? Why is it so many manufacturers - VW/Mazda/Ford seem the worst at this - refuse to give us super tall freeway cruising gears? There's no reason for the V6 to be turning more than 1900-2000 rpm at 65 mph. If a need arises for more power the car should slide back to 5th, otherwise a slow steady climb in power seems to work best.
I don't mind downshifting from 6th at 65 to pass people in my cars. I'd rather get better mileage and do a bit more shifting...
Johnny @ May 8th 2008 5:21PM
Im with you, I want a super tall gear too.
I wish more manufacturers would give us a choice of Axel ratios to accomplish this. I have a 2008 Honda Accord and the gear ratios are:
2.65
1.61
1.08
0.77
0.56
and axel ratio is 4.44
My 4cyl EX (190hp) turns about 2500 RPM at 70mph but Im sure I have enough power to do 2000 RPM at that speed with the 4.1 Axel ratio Honda has in its parts bin on other models.
zamafir @ May 8th 2008 5:30PM
VW not tall? Um... i've been in 6th at 55, and 160 (speedo indicated, act 147, fantastic german engineering natch).and everywhere in between... what's the problem? taller? planning on hitting 180 going down hill?
psarhjinian @ May 8th 2008 5:38PM
+1
Mazda is awful for this, especially with manuals: my old Protege was nearing 3500rpm at 100km/h. My Honda Fit is almost as bad, again, well over 3000 at 100. My Saab? 2200 at the same speed.
Never mind the fact that the lower gears in these cars as so short as to be useless. I can pull away in third in a Honda Fit--yes, a car with a 1.5L. That's just stupid gearing and yes, Mazda did the same thing: you could easily be in fourth or fifth gear at 50km/h. The ridiculous throttle tip-in that some manufacturers (GM, Nissan) doesn't help either. As far as I can tell, the only reason is to give the "feeling" of power.
I don't want the feeling of power at every damn intersection. If I wanted it, I'd have bought a Mustang GT instead of a sub-2.0L econobox.
StickShift @ May 8th 2008 6:00PM
The axle ratio of the the V6 Fusion is 3.46:1. In the 0.69:1 sixth gear that goes to a 2.39:1 overall rating (according to my calculator at least). Gearing like that would do you good on Bonneville....
(Note that the Fusion's gearing is listed as the following: 4.15 2.37 1.56 1.16 0.86 0.69)
Four cylinder models are a different story, as are heavy CUVs. Automakers seem to think we all live in the Rockies, so a low top gear to climb them with is der rigeur. We shall see that change as fuel economy standards get tougher though.
Allen @ May 9th 2008 8:57AM
I can care less. It's more about people (well the auto media) crying about their transmission "hunting" when the grade changes... even though they can't feel the shift. Blame them. Also, blame a weak ass torqueless four cylinder and overweight cars. I guess you could get away with it in a corvette. I want a corvette.
MikeW @ May 9th 2008 7:12PM
If Ford takes a cue from GM/Saturn, 6th gear will be a supercruise gear.
http://www.caranddriver.com/content/download/92328/1185287/version/2/file/Mud+Puppies+-+Powertrain.pdf
That gearing is fine for a front drive VUE, but needs a shorter axle ratio for the 4x4 model. (use 3.16 instead of 2.77)
(The CR-V numbers are WAY wrong, just ignore-Bad C&D!)
So Ford could have a front drive V6 Escape top gear be 40mph per 1K, a 4x4 V6 38mph, Front drive 2.5 I4 also 38mph/, and 4x4 2.5 I4 36mph.
Who cares that top speed of a front drive V6 would be in 4th gear (130mph with a 240hp V6 seems plausible)
Carlos @ May 8th 2008 5:30PM
I still can't understand why automakers won't use CVTs over convention automatics. They have very little fluid losses, and are able to keep the engine at it's most efficient rpm. I know they have problems with handling high torque applications but for every day use they seem like the better alternative. Can anyone tell me why they choose not to make these mainstream?
psarhjinian @ May 8th 2008 5:42PM
CVTs have efficiency issues in high-torque applications, which included just about every North American powertrain. It's better than it used to be; Nissan has a particularly good implementation.
The second reason is more psycological: there's that curious shiftless "slipping" feeling. I don't mind it--I quite like the lack of shift point "thumps"--but most scribes seem to find it objectionable and associate it with a lack of grunt. This isn't the case, as CVT-equipped cars usually can dust their conventional cousins fairly easily.
I like them, too. There's a simplicity to a CVT that doesn't exist in the valve-and-gear bonanza that is a modern automatic or DSG.