By on December 1, 2014

 

Gear arrangement for a 10 speed automatic from Patent # 8,834,310

Gear arrangement for a 10 speed automatic from Patent # 8,834,310

Lately there has been a lot of speculation on what the Ford Motor Company has been up to with their 10 speed transmission design. All we know is that there is a joint venture between Ford and GM to develop the next generation 10 speed transmission for next generation RWD trucks and cars. This article pieces together the information available from the invention disclosures from Ford, and makes  educated guesses about the actual design. While the author sincerely hopes that these guesses are educated in nature,  there is a possibility that the guesses are completely off base. With that disclaimer out of the way, let us look at what facts are at our disposal, and what the Ford 10 speed automatic transmission design is likely to look like when it is sees the light of day. If you are interested, read on.

US Patent number 8,834,310 is one of the many many patents granted to Ford for the design or design elements of a 10 speed automatic transmission. This same basic power flow was first disclosed in US patent number 8,545,362 but clearly it has been refined as the project has progressed. In September 2014, the annual Henry Ford Technology Awards winners were announced. Every year a maximum of ten awards are given out by Ford to recognize and honor technical achievements in the fields of Product Development, Manufacturing, and Research. One of the awards was

 

“For the design and development of the Next Generation 10-Speed RWD Automatic Transmission Family; advanced automatic transmission technology is critical to meet stringent government fuel economy regulations and customer expectations for increased performance.”

 

A major auto company like Ford applies for and receives hundreds of patents every year. Looking for what will actually make it to production can be like looking for the proverbial needle in a haystack. The names of the award recipients is an important bit of information that can be used to narrow the search down. But the recipient of such an award is likely to be a prolific inventor who has dozens of disclosed inventions to his or her credit. Thus even with this information, it is not a trivial task to filter out the noise.  In a modern automatic transmission, there are dozens of relatively minor but innovative things that are invented as the design is fleshed out. Typically the overall power flow is disclosed in one patent, the finer details are disclosed in subsequent patent applications as the design turns from a doodle to actual drawings that can be manufactured on a mass scale and work reliably over the expected life of a vehicle. An absence of such supporting patent disclosures can mean that the design concept is not being taken much further than a disclosed invention. Another clue is if the patent applications are being filed with international patent offices (EU, China, etc). International patent applications are not cheap, and typically inventions that are headed for production will turn into international patent applications as well to protect the intellectual property in jurisdictions besides NAFTA.

After reading through dozens of issued patents and patent applications, I have concluded that the design concept disclosed in part in Patent #8,834,310 is the concept going forward to production. A photochop of the likely cross section put together from the various supporting patents and applications is shown below. I am not sure if I got the width of the fourth planetary gear set and/or the width of clutch pack E correctly, but this should be pretty close to the finished product. The planetary gear set elements and the shafts connecting them are color coded along with the intermediate shaft which is connected to 3 of the shift elements but not to any of the planetary gear sets directly.

Ford ten speed transmission cross section design pieced together from various patent disclosures

Ford 10 speed transmission cross section design pieced together from various patent disclosures

Summary of design features of the Ford 10 speed transmission

The salient features of the design are as follows:

  • There are a total of 10 forward ratios (of course) and 1 reverse ratio
    • There are six forward under drive ratios (i.e. the input turns faster than the output)
    • There is a direct drive ratio where the input and the output shafts spin at the same speed
    • There are three overdrive ratios (i.e. the output turns spins faster that the input)
  • There are 4 simple planetary gear sets, just like the ZF 8HP and the GM 8L transmission families
  • There are six shift elements (as compared to 5 for theZF8HP and the GM8L)
    • 2  brakes (A and B)  that are nested (one shift element is packaged inside the other)
    • 4 clutches (B, C, D, and E), two of the clutches (D and F) are nested as well
  • For any of the 10 gear ratios, 4 shift elements are closed and two are open. Consequently the frictional losses are likely to be no worse than the 8 speed transmission designs
  • The nesting of shift elements means that the overall package size will be pretty similar to the 8 speed transmission designs
  • All shifts up and down need one shift element to be opened, and another one to be closed simultaneously. This is identical to how the ZF 8HP and the GM 8L transmissions work. The shift performance should therefore be very good.

So in effect, what this design provides is an additional over drive gear and an additional under drive gear at the cost of an added shift element. The packaging room is similar to the 8 speed designs, and the difference in weight for a given torque capacity should be minimal (within 5 lbs for a given torque capacity with equivalent levels of engineering diligence). The first 2 planetary gear sets and the fourth planetary gear sets are laid out pretty much exactly like the ZF 8HP transmission design. Therefore it is not surprising that first gear is achieved in a manner very similar to the ZF 8HP transmission, i.e. both the brakes are locked which grounds the ring gear, the sun gear, and consequently the planetary carrier of gear set 1. Since The planetary carrier of gear set 1 is connected to the ring gear of gear set 4, the ring gear of gear set 4 is therefore grounded. The engagement of clutch E connects the input shaft to the sun gear of gear set 1. Though not strictly necessary for the operation of first gear, clutch D is also engaged because clutch D needs to be connected for a shift to second gear or to reverse gear. Clutches C and F are the two open shift elements for first gear operation. This sets up an under drive ratio because the carrier of gear set 4 is the output shaft of the transmission, the ring gear is grounded, and the sun gear is connected the input shaft.

The ratio of first gear is therefore

1st   = S4+R4


S4

 

 

This equation is identical to the first gear ratio equation for the GM 8L90 transmission, as well as the ZF 8HP transmission. The GM design has a first gear ratio of 4.55:1, while the ZF design has a first gear ratio of 4.70:1. The second generation ZF 8HP transmission offers first gear ratio of 5.0:1, which is  the practical upper limit of the gear ratio such an arrangement can yield. Therefore, I do not expect that the Ford 10R family offers a much shorter ratio than 5.0:1 for the first gear. The 10th gear ratio is expected to be in the 0.6:1 to 0.64:1 range. For comparison, the GM 8L90 has a 0.65:1 ratio for the tallest gear, and the second generation ZF 8HP has a 0.64:1 ratio for the tallest gear. The calculations for all 10 gear ratios are detailed in the companion saturation dive.

Overall ratio spread and an example of design refinement

Therefore in terms of the overall ratio spread (ratio of the shortest gear to the tallest gear), this transmission design is not going to break new ground, and will likely be similar to the second generation ZF 8HP. I would project an over all ratio spread of around 7.5.  So while the ratio spread is similar to the 8 speed designs, the ratio spacing is going to be better because there are 10 steps between the numerically highest and the numerically lowest gear instead of 8.

Additionally this transmission design has many refinements that are not immediately obvious, e.g. the nested layout of the 2 brakes has a measurable advantage over the ZF or the GM friction element layout. The ZF 8HP design and the Ford 10R designs are compared in the figure below

Comparison of the brake arrangements for ZF 8HP and Ford 10R designs

Comparison of the brake arrangements for ZF 8HP and Ford 10R designs

With the ZF design, brake B is disengaged for 8th gear operation. At 3000 rpm transmission output speed (approximately 80 mph), brake B sees a relative speed of 4500 rpm. Therefore even a small amount of drag torque can translate to a substantial power loss and therefore a reduction in the fuel economy. The stationary plates are splined directly to the housing, which is smart because it saves a component but at the cost of added complexity to the transmission housing. But this design decision also has a downside, it limits the ability of transmission fluid to flow through the brake. It is customary to put holes in clutch drums to provide a path for the fluid to flow out of the clutch when it is open. With the transmission housing serving the role of the clutch drum, such holes are not possible because while you want the fluid to be able to leave the shift element, you do not want it to be able to leave the transmission housing (that leads to unhappy customers, warranty, etc). In the ZF 8HP design, the centripetal acceleration due to the angular velocity is slinging the fluid outwards, and that fluid has nowhere to go so it sits inside the brake and causes drag. Even a third of a lb-ft of additional drag torque is a quarter horsepower of power loss, i.e. approximately a quarter of an mpg loss in highway fuel economy.

The Ford 10 speed transmission design on the other hand moves the ground element of the brake to a nested clutch and hub design. Since the 2 brakes are now entirely  internal to the transmission, it is now possible to design in the appropriate passages for the fluid to leave. Therefore for the overdrive gears, when  brake A (outer brake) has to be open by design, the fluid has a way out of the clutch and therefore the plates spin in air instead of a bath of fluid. This leads to lower drag torques, and could easily account for a 0.1 mpg or more highway fuel economy enhancement over the ZF 8HP design. The original patent disclosure for the power flow had a brake arrangement very similar to the ZF 8HP, while the later invention disclosures go to the nested design. This is an example of the design being refined as the development progresses.

What is the competition doing?

The Daimler 9G-Tronic 9 speed gear box also had 4 simple planetary gear sets and 6 shift elements. But it only accomplishes 9 speeds from the layout as compared to the 10 from the Ford 10R design. At the expense of 1 gear ratio, the Daimler 9G-Tronic design gains a wider ratio spread of 9.16 (first gear ratio of 5.5:1, 9th gear ratio of 0.6:1). On the flip side however 3 of the 6 shift elements are disengaged/open for any given gear, as compared to 2 for the Ford 10R design thereby giving Ford the slight edge in parasitic frictional losses.  You win some, you lose some.

ZF CEO has emphatically stated that his company is not going after 10 speed designs for now. Therefore the long list of clients ZF has are presumably happy with the 8HP and the forward evolution of the design. But ZF engineers do have a few disclosures with 10 speed power flows similar to this one (6 shift elements, 4 planetary gear sets, 2 open shift elements in any gear) going back to 2007-9 time frame.

Hyundai and Kia also have invention disclosures with a power flow that is in effect very similar. So it is possible that  10 speed transmissions are also on the horizon for the luxury offerings from the 2 brands.

General Motors has officially partnered up with Ford to use this design in the future. Ford appears to be leading this design effort, and in return GM appears to be leading the design effort for the 9 speed FWD transmissions. Though the GM 8L family is an excellent design in its own right, but perhaps the economies of scale inherent in a partnership are attractive enough for them to adopt this design after a relatively short time with the 8L family.

Conclusions 

The rumor has it the first prototypes were installed in test vehicles late last year, and the controller software development is in full swing right now. Unless the software team is working extra fast, 2015 CY is unlikely. Likewise for the production tooling, I doubt that it is possible to tool up this transmission within 18 months  of first vehicles level prototypes. While it is possible that this transmission shows up for 2016 model year in late 2015, it seems more likely that it actually does not show up till the middle of 2016  for 2017 model year vehicles.

This is a good solid design, kudos to the design engineers at Ford for making this happen. A project of this kind is not a trivial undertaking, and I am sure there is a tale of blood, sweat, and tears behind this design. While the mechanical design seems fairly complete, the Tresmonos of the world are probably slaving away to get the tooling all set up as this article is run. At the same time the code monkeys are likely working just as hard on the software to make sure that this transmission shifts like the best. It is safe to say that there are more missed anniversaries and birthdays ahead for a large team at Ford and GM.

Forward progress seldom comes without an effort. This is forward progress.

The first commentator to say CVTs are better shall find coal in his or her stockings. A CVT design with this much torque capacity is yet to be seen. Physics, it can be a pesky thing.

For all 10 gear ratios, and details of the operation of the transmission, please refer to the saturation dive.

The author would like to stress again that all information presented in this article is from publicly available sources, mostly the USPTO website. Internet, it can be a wonderful source of information.

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61 Comments on “Exclusive: An Inside Look At Ford’s New 10 Speed Transmission...”


  • avatar
    HerrKaLeun

    Great article, as usual.

    I understand CVT are limited to less tourque (Accord and below). Couldn’t there be some double CVT or double belt? CVT itself seems ptetty simple, small and cheap. An article about CVT and maybe the Prius planetary would be good to see why the 10- gear trannies still are important.

    • 0 avatar
      DenverMike

      a 10-speed trans would make a CVT obsolete and pointless. Especially in cars. Look for the CVT to go the way of the dodo, as more gears are added to cars too.

      And there’s no real point in going beyond 10-speeds in cars. Trucks can use more than 10, but there’s a limit, diminishing returns there too.

      • 0 avatar
        FormerFF

        I’d rather have the CVT, if you need a substantial ratio change it gets the engine up to speed more quickly, and the ratio changes are smoother.

        • 0 avatar
          Brian P

          You can dump fluid out of one clutch and pump it into another (changing gear) much quicker than you can apply pressure to a CVT pulley/cone and force the belt to slide across the face of the cone from one ratio to another.

          Newer Jatco CVTs have a planetary gearset in addition to the CVT … and if you mash your foot to the floor, they downshift the planetary gearset. It’s quicker. But if you are going to have to integrate a two-speed planetary gearset with the CVT to get enough spread between lowest and tallest ratios, why bother with the CVT?

        • 0 avatar
          George B

          With either the CVT or the 10-speed automatic, the control computer is going to be adjusting the engine rpm somewhat separate from the accelerator pedal. I would expect the 10-speed automatic to coordinate engine rpm and clutch engagement to make the gear changes smooth.

      • 0 avatar
        psarhjinian

        “a 10-speed trans would make a CVT obsolete and pointless. Especially in cars. Look for the CVT to go the way of the dodo, as more gears are added to cars too.”

        Other way around; a CVT makes something like this pointless. Think about it: a CVT doesn’t have to hunt between ratios or lose power shifting. This thing is going to hunt for gears like a truffle-pig.

        ETA: Assuming that a CVT can handle the torque output. If this is a truck transmission, I get it, but still…

        • 0 avatar
          DenverMike

          CVTs sounded amazing in theory. But there’s no real reason for 10-speeds to constantly hunt. And gear changes are less noticeable when rpm drops less between gears.

        • 0 avatar
          stuki

          I would tend to agree with you. The hunting can be solved in software, but the sheer complexity of the thing does make CVTs seem pretty appealing.

          One of the main developments in power trains going forward, will likely be the move towards twin power sources. Even non-hybrids will need enough battery and motor to at least make use of brake regen energy. How well a transmission adapts to this, will go some ways to determining how successful it will be. And again, it seems to me CVTs will be more felixible.

          For truck duty, it may be easier to hit torque requirements with conventional gears, though. Who knows.

        • 0 avatar
          cronus

          The reason why CVT are becoming obsolete is not because they can’t handle high torque outputs but because they don’t have the ratio spread that a 8 or 10 speed does. CVT’s are around 5:1 while this transmission is 7.5:1 and Daimler’s is 9:1. To put that another way you would need two CVT’s in series to get the same low RPM cruising speed.

          • 0 avatar
            Timur Apakidze

            Cronus

            JATCO CVT8 has a 7.0 ratio spread. Not sure what applications have already started using it. But I do believe that 7.0 is close to the limit of what is possible with the CVT technology.

        • 0 avatar
          Timur Apakidze

          A CVT may not lose power shifting, but it takes a lot of hydraulic power to maintain the appropriate belt tension to prevent slippage. So it is not like CVTs are the silver bullets.

          But I have to say this – there are a lot of passionate followers for the CVT technology.

          • 0 avatar
            psarhjinian

            “But I have to say this – there are a lot of passionate followers for the CVT technology.”

            It’s a matter of suitability; CVTs work fairly well in low-torque applications (snowmobiles have used CVTs for years).

            The belt-tension issue is less of a problem with push-belt, and almost a non-issue with toroidal CVTs like Nissan’s.

            The problem, I think, is that CVTs don’t feel right, especially to automotive journalists. There’s also been some issues with certain implementations:
            * GM & Honda: from what I can tell, both just upsized the snowmobile CVT and didn’t really consider the heat issue. Honda has a history of this sort of thing, and GM just wasn’t trying at the time.
            * Ford: this seemed to be maintenance; I personally witnessed dealer mis-servicing of the Freestyle/Five hundred.
            * Nissan: there were some issues with very early Muranos, but nothing since, and the Xtroid units seem quite solid.

            I tend to use Consumer Reports as a reference, and Nissan doesn’t seem to have particularly many transmission issues versus traditional automatics. Compare the Murano to, say, the Honda Odyssey or Acura 3.2TL, for example; the Nissan has a little half-black blip in it’s first year; the Honda is black dots all the way.

            Full disclosure: I find the Xtroid CVT in action to be, visually, about the coolest thing I’ve ever witnessed. And of all the criticism levelled at the Maxima, one of the nice parts of it is the smooth, linear push the CVT allows. I really wish Nissan hadn’t added fake “gears” to certain implementations.

      • 0 avatar
        TopJimmy5150

        Actually, it’s quiet the opposite..CVTs make other transmission obsolete and pointless. R&D needs to be put into making CVT for all cars. I’m sure the Japanese auto makers are on it, as usual.

        I think it’s hilarious that the same companies that couldn’t build reliable 4 speed transmissions are diving into making 8-10 speed transmissions, and consumers just lap it up. Then 80,000 miles comes along and their internals disintegrate into powdered metal.

      • 0 avatar
        redav

        Honestly, I expect electric motors, i.e., EVs, to obsolete variable speed transmissions. The transmission only exists because of the shortcomings of the engine–if those are eliminated, the bandaid (transmission) goes away.

  • avatar
    DeadWeight

    1) Ford spends billions (360 million per factory to retool, hundreds of millions more in R&D and more expensive panel attachment and material costs to “aluminify” its profit nucleus lineup of F Series trucks, in order to win a sizeable lead over the competition in fuel economy bragging rights.

    2) When this ‘fails to significantly move the gas gauge needle” as Automotive News states it –

    http://www.autonews.com/article/20141121/BLOG06/141129950/ford-f-150-mpg-for-2015-is-a-mixed-bag

    – Ford emphasizes the towing & payload capacity of the new F Series, instead, playing down the fuel-efficient theme.

    3) Ford now enters the more-gears-the-better transmission hunting race as it steers the discussion of FUTURE possible fuel efficiency gains for the now already lightened, “aluminized” F Series back into the “just trust us” media sound bite release track.

    4) Ford does the same regarding “additional future” alterations to the F Series to recover the FUTURE fuel economy gains they claimed would have already arrived.

    Bottom line: Ford could have saved untold billions by scrapping the poorly thought out “aluminumization” plans,and just went with high strength, lighter weight steel,and more importantly, doing what RAM did with their2.7 ecodiesel rollout (that delivers stellar torque and truly stellar fuel economy), and as GM is now implementing on a more aggressive scale, including with their Colorado midsize truck.

    Good luck to Ford in recouping the money (billions) they now already spent “aluminumfying” their F Series, while keeping up with incentive spending to battle GM & RAM for future sales, and while retaining margins, WHILE COMPLICATING DEALERSHIP BODY SHOP AND CUSTOMER LIVES who take on aluminum body panel all over pickup trucks.

    Maybe Ford can get t9 the promised land of salvaging operation “aluminumification” by offering a 20 speed transmission soon.

    Beta testers of the new F Series unite!

    • 0 avatar
      heavy handle

      DW,

      For what it’s worth, Motor Trend found that the new Ford Ecoboost F150 delivered great power and fuel economy, much better than the Chevy V8. That result held both empty and loaded. I know that it’s common knowledge here that EB doesn’t deliver under load, but I guess they got a different result.

      I think that you realize that Ford didn’t just enter the “more-gears-the-better” race. As this article demonstrates, they’ve known this was coming for quite a while. Low weight and better transmissions aren’t mutually exclusive, both are beneficial.

    • 0 avatar
      DenverMike

      DW,

      Leave it to marketing to overplay/over hype every new feature or advancement. Take them with a grain of salt so you don’t feel so betrayed, hurt and lied to.

      It’s like watching an amazing movie trailer and wanting your money back at the theater. It might have still been a good movie.

      New features or tech shouldn’t have to set the world on f!re, to be viable. “Alumification” and 10-speeds are true advancements none the less. And coming to an Accord near you!

      But better they start with vehicles that can easily afford it. The F-series is the most profitable car in the world. Followed by the Silverado.

      So they’re ‘diverting’ a small percent of pickup trucks profits, back to pickup trucks. Their obscene taxable profits are measured in the multi billions annually. Can you say “tax write-off”?

    • 0 avatar
      jdash1972

      Diesel fuel costs more in the US than unleaded, 10-15% more at a minimum, and the Diesel engine option is significantly more expensive as well. The RAM Ecodiesel may get excellent mileage for a truck but it already has to get 10-15% better fuel economy just to achieve parity in terms of cost with a gasoline engine. Then you have to calculate how far you can drive the gasoline powered truck with the money you saved not buying the diesel engine option. When you factor in all these costs fairly it takes a long, long time to reach the break even point with a diesel, if ever. Heaven help you if the diesel ever craters because you’ll be in for a real financial treat. The Ford 2.7 eco boost V6 is no slouch when it comes to torque so let’s not change the subject to towing. 375 vs 420 is not an argument worth having.

      • 0 avatar
        MBella

        The new diesels are also very maintenance intensive. The exhaust system is so complex you spend a very high dollar amount on keeping it working. Even though diesel exhaust fluid has become cheap, you have so many sensors that like to fail regularly, along with the particulate filters and cats. All these parts are not cheap, and have a service life that isn’t particularly good. I can’t see it paying off for the average driver.

        • 0 avatar
          DeadWeight

          I would make a distinction between cars & trucks in this regard.

          While diesel motor maintenance is getting less expensive, it’s still less a “value” or “capability” proposition vs gas motors in cars.

          Trucks are an entirely different matter, which is why used diesel trucks command relatively massive premiums in terms of resale value compared to gasoline motor trucks.

          Consider the torque, fuel economy, and especially, longevity/durability of diesel motors in hard service duty.

          Also, diesels are typically good for a minimum of 300,000 miles (and often many more miles), which is twice the useful life of a gasoline motor.

          Ford screwed the pooch. Lightening a brick shaped vehicle such as an F Series pickup with an expensive aluminification process doesn’t yield the fuel efficiency improvements Ford originally claimed it would, and now they have a much higher cost truck to produce compared to the GM and RAM competition.

          • 0 avatar
            DenverMike

            Historically, that’s been the case. But we don’t exactly know how long the current wave of diesels will last. We know it was the lubricity of the fuel that kept them going for forever. Most of the lubricity is gone now.

            You couldn’t go wrong with used diesel pickups of yesteryear. With today’s diesels, it’s a roll of the dice. Who’s worked on it before? What’s been done? Who made the parts? Will it need emissions equipment? How much will that cost?

            To replace everything, you’re looking at $20,000 easy. Just having to replace a few things can “total out” the diesel truck.

            It’s about impossible to know what the heck you’re buying.

            It’s not like the old days. I wish it were!

          • 0 avatar
            mooeymoose

            I personally will never buy a diesel and I hope they do not get popular in the states. You may get higher MPG but this is like comparing apples to oranges. Diesel is a denser fuel and will produce about 14% more CO2 then regular gas per gallon. So, a better method for efficiency of engines would miles per lb of Co2 produced.

            2nd there still health issues with diesel. They certainly run, sound and smell better but that does not mean they are not mean they are not still killing you. The smell goes away with removal of the sulfur but its still listed as a group 1 carcinogen by the IARC. This is from the fine particles produced that are not removed with any of the new methods.

      • 0 avatar
        srogers

        Where I live in Alberta, diesel is more than 30% more expensive than regular gas. I wonder how many people figure this out when they’re comparing fuel economy figures.

    • 0 avatar
      mikeg216

      My 04 f-150 gets 14 mpg the 15 gets 22 that’s a 65% improvement add in this transmission and we’re looking at 25-26 mpg. This was about Cafe, they’ll have no problem selling all of them they can

      • 0 avatar
        DeadWeight

        Why don’t you compare your current ’04 F-150 to the 2014, and not 2015, F-150?

        Oh, because the 2014 is pretty much just as efficient as the 700 pound lighter, aluminum intensive 2015 model?

        Okay, that’s why Ford Marketing did the same thing as you.

  • avatar
    bumpy ii

    So, when do we revive the multi-speed differential?

  • avatar
    danio3834

    Great article, thanks for posting this. It’s hard to find this stuff elsewhere. This answers a lot of the questions I had about this transmission.

    • 0 avatar
      highdesertcat

      IIRC, Mercedes-Benz and Lexus have had 10-speed hydraulic-step automatics for some time now. I don’t know why this Ford/GM venture is something special. I believe it’s been done before, by someone else already.

      I’ll be a happy camper if Toyota features the 5.7L in front of a Lexus 8-speed automatic for the 2016 Tundra. That would ring my bell.

      • 0 avatar
        Timur Apakidze

        Highdesertcat

        I believe the Mercedes-Benz is actually a 9 speed step AT. I am not aware of anything with greater than 8 cogs from the Lexus camp. There is talk of a ten speed Lexus tranny sometime in 2017. But hey, what do I know ;)

        • 0 avatar
          highdesertcat

          Timur Apakidze, rest asured that I am not in the league that can even afford to think about buying a Mercedes or Lexus.

          SO, as such, I am more than willing to defer to your research into this subject.

          Like I said earlier, an 8-speed hydraulic step transmission is what I hope to find in my 2016 Tundra 5.7.

          And I say this because I own a 2011 Tundra 5.7 6-speed, and I believe that with the broad power band of the 5.7, it could easily handle two more cogs thereby reducing cruising rpm on flat roads and more closely matching torque, load and road-speed when driving or towing in hilly country.

          • 0 avatar
            Timur Apakidze

            Highdesertcat

            The Toyota empire already has an 8 speed that is suited for use in a Tundra. The Audi Q7 8 speed automatic transmission (along with the platform mates for VW) is an 8 speed Aisin transmission which has the appropriate torque capacity for pick-up truck duty.

            Hopefully this is high enough priority at Toyota that your wishes are granted.

            Most I have spent on a car would get me the doors of a proper Lexus ;)

          • 0 avatar
            highdesertcat

            Timur Apakidze, I hope Toyota sees it my way, even if they have to fudge the Differential ratio for the 5.7 to accommodate the extra two cogs, and spread the power better where the rubber meets the road.

            I have come to the end of my new car/new truck buying escapades. We recently got my wife a 2015 Sequoia as her last SUV of her driving life. Fortunately for me, we didn’t have to pay for it. The business did.

            The 2016 Tundra will most likely be the last truck of my driving life. And I will have to pay for all of it.

  • avatar
    Nick 2012

    I am slow clapping at my desk in awe of your skill and expertise.

  • avatar
    bball40dtw

    Voodoo Magic

  • avatar
    Occam

    Wow… If you’re just going to keep adding cogs, skip it already just work on CVTs. I love to row my own gears, and will buy manual transmission cars exclusively until either none can be found, or my knee cartilage is worn so rough you could use it for a clutch plate.

    But given the choice between an conventional automatic or a CVT, I’ll choose the CVT every time. If *I* don’t get to enjoy shifting gears, I don’t want to listen to/feel the computer getting to enjoy it!

    (DCTs are OK I suppose, but they seem to be going out of their way to make them feel like conventional slushboxes, with the annoyind D-creep and everything)

    • 0 avatar
      krhodes1

      @Occam

      Nothing, and I mean NOTHING, drives me crazier than fake creep! So incredibly stupid, especially in a full electric or dct where it is doing nothing but causing wear and tear and/or using up battery to no purpose. Just so the car feels “normal” to the idiot behind the wheel!

  • avatar
    schmitt trigger

    Thanks for a very good article.
    There is more technical stuff that I can digest in a single reading, though.

    I’m no Ford fanboy, and don’t require a truck, either. Nevertheless I applaud Ford for having the wherewithal to tackle such a project.

    As I’ve previously mentioned, I was a witness of the space race, and remember distinctly the naysayers who mentioned that the moon landing could not be accomplished. At least not in the time frame outlined by president Kennedy.

    Keeping both projects in proper perspective, this is an excellent example of the American can-do engineering spirit.

  • avatar
    schmitt trigger

    Lost my original comment…. :-(

    Anyways, thanks for a wonderful and informative article.

  • avatar
    Felis Concolor

    As I stated earlier, my purchase of a Rohloff 14 speed IGH (internal gear hub) for the recumbent has me especially interested in the growing sophistication and gear count for modern automobile transmissions.

    I know the torque inputs are significantly lower for IGH equipped bicycles compared to their automotive brethren – even the heaviest duty pedal power system experiences no more than 250Nm – but when Rohloff can use 3 planetary gear sets to extract 14 forward ratios out of a theoretical maximum of 27, how come automobile transmissions aren’t performing the same operations, as the addition of a 4th planetary set should result in a potential maximum of 81 (possibly not unique) gear steps, not counting such specialized tricks as ZF’s double reverse for its 9 speed? Are certain operating modes too fragile to handle modern engine torque loads?

    • 0 avatar
      Timur Apakidze

      The bicycle hub is dealing with much lower power levels. A human being output is maybe 1 hp, this will sit behind engines making 600 hp.

      Other issue is shift quality: at thousands of rpm an automotive transmission has to change ratios, while still transmitting 60-70 hp to the wheels without objectionable shift quality.

  • avatar

    I completely fail to understand one thing.

    The ground element 70 (patent, 82 on cross-section) is completely enclosed by the rotating element 58 (56). So are brakes C, D, F. So, in effect, the ground element is impossible to ground — by which I understand the connection to the transmission outer case or other stationary element.

    Even if we assume that the “ground” element is only grouunded effectively, by the action of 2 out of 3 brakes in concert, then how is the power routed to the brake pads? Same question applies to the brake E.

    All the article says is, “[t]he Ford 10 speed transmission design on the other hand moves the ground element of the brake to a nested clutch and hub design.”

    • 0 avatar
      Timur Apakidze

      In the forward gears Element 70 (patent, 82 on cross section) is not a ground element at all in forward gears. It is an intermediate shaft that rotates at various speeds for the forward gear ratios.

      The 2 brakes are brakes A & B in the patent (left most shift elements in the drawing), the remaining 4 are clutches (i.e. both sides can be rotating).

      In reverse gear, when A&B are both grounded, element 58 is grounded. Then in turn clutches F&D are engaged to ground intermediate shaft 70 and planetary gear set 3 to provide a reversal of the direction of rotation.

      As for the power to the six shift elements, there are apply pistons for each that you can see in the cross section. For the 2 brakes, the apply pistons are stationary, and get power through hydraulic passages on the left of the cross section. The apply pistons for the 4 clutches are rotating and get powered by another set of hydraulic passages. The transmission pump generates the hydraulic pressure to apply the pistons, and the solenoid valves route the power appropriately. The operation of the solenoid valves is controlled by the transmission controller/computer. The rotating seals that you see in the cross section between the input shaft and the intermediate shaft keep the various hydraulic passages sealed from each other.

      I have color coded the apply pistons as well at the link below

      http://www.thetruthaboutcars.com/wp-content/uploads/2014/11/Ford_10R_Cross_Section_pistons.png

      Hope this answers your questions!

      • 0 avatar

        Thanks a lot, I think I understand now, as much as a layman can anyway. Just one thing: the cutaway has 4 passages through the input shaft on the left, but they only lead to 3 clutches (C, D, F). The clutch E is fed through the side of the output shaft. Is one of them an outflow passage?

  • avatar
    carguy

    Nice work sir. Another great slush-box deep-dive!

  • avatar
    PrincipalDan

    So the only questions I’m left with are… 1.) Do we expect that the top gears will only come into play in limited situations? (like the current Chrysler/Fiat 9-speed) 2.) Will there be limits to overdrive in towing situations? (I remember back in the early days of 4-speed automatics (1980s) when drivers were explicitly advised to put it in drive for any towing situation.)

    • 0 avatar
      Timur Apakidze

      Dan

      I will be doing a companion write up on the gear ratios. Short answer – no the overdrive gears are not going to be like the Chrysler/Fiat 9 speed. The Chrysler/Fiat 9 speed has 4 overdrives, this puppy has 3, i.e. the ratio spread is very balanced. I would expect that all 10 would be used by the time the vehicle hits 70 mph at close to curb weight.

      Towing – I don’t know enough to give you an informed answer. I would speculate that yes if you are towing 10,000 lbs it is probably not advisable to use the 2 taller overdrives, or maybe not use an overdrive at all.

    • 0 avatar
      cronus

      If the top ratio is .64 that’s close to the top ratio of .69 in the current 6 speed. I would expect the trend of taller rear axle ratios to continue, maybe dropping below 3.00:1 to take advantage of the lower first gear.

    • 0 avatar
      Brian P

      One of the issues with the old skool (nowadays!) 4 speed automatics wasn’t necessarily to do with the gear set, but rather the torque converter and its associated heat buildup.

      The traditional shift sequence was 1st (unlocked), 2nd (unlocked), 3rd (unlocked), 4th (unlocked), then lockup, and lockup only happened at significantly less than full torque output of the engine. It had to be like this because the old-skool powertrain controls relied on the torque converter slippage after the shift to smooth out the gearchange. If you were towing, the torque demand could often be high enough that the torque converter would be unlocked in overdrive, but with tall gearing, the torque converter would be slipping a lot and generating plenty of heat. But if you manually locked out overdrive, it takes less engine torque to pull the load, and you could get converter-lockup in 3rd (which wouldn’t happen in the normal shift sequence).

      A driver who is paying attention could detect the torque converter unlock (revs go up) and then manually hit “overdrive off”, at which point it would downshift to 3rd but lock the converter, making little difference to engine revs, but a big difference in heat buildup in the transmission. Been there … But if it’s your average person driving, who doesn’t pay attention to the tach, better to just leave overdrive off all the time.

      One of the big benefits of having lots of ratio choices is that with closely spaced cruising gears, and drive-by-wire to manage engine torque, there’s no need to have the torque converter unlocked in those gears. So you can just leave it in “drive” (or “tow/haul”) and let it do its thing. And the controls are smart enough nowadays to know how to manage which gear to be in to avoid heat build-up in the transmission.

      By the way, I know that the tooling is already being built for this transmission. It will show up sooner rather than later.

      • 0 avatar
        Timur Apakidze

        Brian P

        Interesting to know that the tooling is underway. I would estimate at least 52 weeks for some of the long lead item parts, and then the validation of the tooled parts takes another 30 weeks or so?

        Do you think this transmission can show up next summer? I kind of doubt it but I have been wrong before!

        • 0 avatar
          Brian P

          I doubt summer 2015 would happen, but I’d say model year 2016 is pretty likely. I also don’t think it will be an instant changeover from the 6R to the 10R – more like a gradual phase-out of the 6R and phase-in of the 10R over probably a couple of years as they ramp up production. Same thing Ram has done … the new transmission shows up in some models with some engines first, before it goes across the board.

  • avatar

    One other thing: I’m wondering just how long that thing is. I have a 4-speed 42RLE in my jeep, which (according to Allpar) descended from a transverse Ultradrive. Despite that, it’s very long. My rear driveshaft is so short that Chrysler had to put a CV joint into it instead of a plain cross joint. There’s a certain length after which you can only package something like an crew cab truck, not a jeep.

    • 0 avatar
      Timur Apakidze

      For a given torque rating, I would guess that this design would be similar to or maybe even a tad smaller than the ZF 8HP. If the next generation wrangler can take the 8 speed, I am sure that these transmissions can be packaged into a vehicle with the footprint of a Wrangler.

      Not really sure about the 42RLE, I have never really paid attention to the family of transmissions.

  • avatar
    pannkake

    I really enjoy your articles. Keep them coming!

  • avatar
    Fred

    My first car a pos 1959 Ford Fairlane had a 2-speed “slush box” with worn out bands to boot. I soon found the joys of a 3-on-a-tree and thru the years progressed all the way to a 6 speed manual. Never thought there would be a need for more gears.

  • avatar
    PartyST

    Your ability to break down the design and operating characteristics of a transmission into clear, easily understood language is unique, and enjoyable. Thank you!

  • avatar
    olddavid

    I once made a concerted effort to learn the basics of the torque converter automatic. All those little pieces and passages made me an unqualified failure. The last bastion of voodoo engineering. Still, the little I do know, combined with some knowledge of electric hand pre-selectors from 1936, have me wondering why any sane person would buy a DCT? All the weaknesses of a stick without any personal control. What I have read on SearchAuto seems to confirm the fragility of these boxes. Just to get 2 more m.p.g.? I don’t get it.

  • avatar
    George B

    Thanks for writing such an informative article Timur.

  • avatar
    MadHungarian

    I just have one question which is, in 2027 when I’ve racked up 175K miles and that ten speed thingamajig craps out, how many of my grandchildren will I need to sell into bondage to pay for a rebuild?


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