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Exclusive: An Inside Look At Ford's New 10 Speed Transmission


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I assume it would replace the 6R80. That's 800 lb/ft at the input shaft and allowing for torque converter multiplication you're looking at 400-500 lb ft at the flywheel. That's far more than sufficient for F150s.

Maybe that's 800 nm or around 600 lb ft torque. I skipped to the summation at the bottom of the article,

the essences is that this design appears to be more efficient than other patents from ZF - that's a big call

but maybe this design is that ingenious

.

 

Closing remarks on the Ford 10 speed transmission design

The gear ratio numbers presented here are estimates based on the patent filings, the actual

gear ratios when the 10R transmission family sees the light of day might very well be slightly

different. As noted in thelast article, this transmission is unlikely to meet the gear ratio spread

of the 9G-Tronic, but the spacing between the gears is pretty much spot on. In my humble opinion,

the ground the Ford design gives up to the 9G-Tronic in gear ratio spread, it will probably make up

in efficiency because of 1 less open shift element in any given gear.

 

The genius of this design is the use of an intermediate shaft which is connected to 3 of the 6 shift

elements. This intermediate shaft allows for 10 well spaced ratios between the highest and lowest

gears, and also simplifies the hydraulic system of the transmission because hydraulic power for half

the shift elements goes through one rotating shaft. This kind of design is far too complex to be totally

invented by a human because there are simply too many permutations and combinations to consider

when evaluating a power flow. Therefore candidate designs are typically brute forced by computers and

subsequently short listed and refined by carbon based life forms. The use of such an intermediate shaft

that is not directly connected to any of the planetary gear elements is truly unique, and leads me to believe

that the transmission synthesis software used at Ford is a step or two ahead of the transmission synthesis

software used by the other big boys of transmission design. There are patent disclosures out there from ZF

with 4 gear sets and 6 clutches that do yield 10 forward ratios and 1 reverse, but the ratio spacing is rather

less than optimal. In US Patent #8465390, ZF has disclosed a power flow which has ten forward ratios,

but 5th and 6th gears ratios are practically equal to each other, and so are the 8th and 9th gear ratios.

Additionally there are 3 open shift elements for any given gear ratio, thereby the transmission concept

disclosed in this patent would have a lower efficiency than the Ford design.

 

Edited by jpd80
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Same here. So this uses gear sets in order to create the 10 ratios, and not 10 physical forward gears? Or did I completely miss the bus?

 

I think it uses 4 gear sets in 10 different combinations to achieve 10 different final forward ratios. Each shift requires changing 2 gears at the same time to get the next ratio.

 

Think of it like a bicycle where the actual gear is a combination of the front and rear sprockets where the front has 4 sprockets and so does the rear and you change both the front and rear to go from one gear to the next.

 

The 5R55 did something similar. It had a 3 speed transmission and an overdrive. The 5 forward speeds were 1st, 1st+OD, 2nd, 3rd, 3rd+OD. They just spaced out 1st and 3rd gear in the main gears so the OD could be used in conjunction with 1st gear to get a 2nd gear ratio.

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I think it uses 4 gear sets in 10 different combinations to achieve 10 different final forward ratios. Each shift requires changing 2 gears at the same time to get the next ratio.

 

Think of it like a bicycle where the actual gear is a combination of the front and rear sprockets where the front has 4 sprockets and so does the rear and you change both the front and rear to go from one gear to the next.

 

The 5R55 did something similar. It had a 3 speed transmission and an overdrive. The 5 forward speeds were 1st, 1st+OD, 2nd, 3rd, 3rd+OD. They just spaced out 1st and 3rd gear in the main gears so the OD could be used in conjunction with 1st gear to get a 2nd gear ratio.

 

The bike analogy is perfect. This doesn't seem too common in automobiles.

 

Naive question, is this the transmission that Ford and Chevy were collaborating on? I didn't read anything about GM in the original posts

 

As I understand it, this is it.

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The bike analogy is perfect. This doesn't seem too common in automobiles.

 

 

As I understand it, this is it.

I don't believe it is very common... Yet. But with everyone trying to stuff more gears into their transmissions something will have to give. Using only 4 or 5 gear sets can save room, enabling use on smaller vehicles.

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GM is lead on the 9 speed fwd version. Ford is lead on the 10speed. GM will be first with the fwd unit and Ford with the 10speed. GM on their own modified the last JV RWD truck trans to make the 8 speed in their trucks. From what I understand it is similar with the OD coming in on various gears.

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Wait a minute, the 8L90 8 speed auto GM introduced in their full size trucks this year is not a JV, it came out of GM Powertrain/Hydra-Matic. I believe it is 'clean sheet', not a derivative of the 6L90 (the 6L90 uses a Ravigneaux gearset I think the 8 speed uses something else). However, the 8 speed auto in the Cadillac CTS sedans (not coupes) is designed and supplied by Aisian. A modified 8L90 is used in the Corvette.

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One comment that does disturb me was that the increase in gear ratio did not appear to increase the gear spread, which is the most common reason or adding gears.

 

Software/calibration are going to be key to customer acceptance of this transmission. While I admit to not having driven anything with more than 6 speed, I would think 8 - 10 speed transmissions would "feel" "busy". with lots of shifting on tip-in/tip-out.

 

Clearly this transmission is designed to operate for long periods in 8th, 9th or 10th gear as opposed to most automatics that want to get you to the "top" gear as quickly as possible.

 

As for a replacement for the 6R140, ratio spread is key in that market. Medium duty trucks need a "deep" first gear (overall) to get them launched when fully loaded. They also need a very "high" high gear for highway travel when unloaded. I would think in this market space that a 2 speed rear axle might be more "cost effective" or at least pass the cost on to the customers who see the value.

Edited by theoldwizard
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Oldwizard, how about a splitter incorporated as a final stage in the transmission instead of a two speed axle? Think of the old 8 speed RoadRangers, a four speed transmission with a 2 speed splitter mounted on the back. Although it was a stick, it was simpler to shift than a 4 speed with a 2 speed axle. (ever miss a shift with a 2 speed axle? it can be panic inducing.)

 

The mechanical design of an automatic that could have the tailhousing replaced with a splitter as the application required would not be all that difficult, but software and calibration would be a bear. Things could be simplified if use of the splitter was restricted to say the first two ratios and the top ratio

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I'm curious to see how well this works from an efficiency, driving feel, and reliability perspective.

Efficiency: In an auto transmission, more gears = more efficient shifts, in theory. Though wouldn't that depend on the ability of the transmission to change quickly/properly calculate the optimal time to shift.

Driving feel: A lot of people say CVTs (and I know this isn't one) feel lifeless, perhaps this will be better.

Reliability: I'll sit this one out and see how it does before I buy a car with one. The advancement of technology is great, but I'll sit out on beta testing a transmissiont that costs $$$$ to replace out of warranty.

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Why are we talking about the 6R140? Isn't that just in the Superduty, not F150? I think the 10 speed is going to be F150 only so a 6R80 is plenty beefy enough.

 

You are correcct, but I think this tranny is supposed to form the basis of the 10R200 (I made that name up) that will go in the Super Duty.

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