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Eaton-Cummins transmission joint venture hunts for last stick shift holdouts

AMT adoption owes to inability of most drivers to master a manual

A Peterbilt Model 579 equipped with the new TX-18 transmission based on the Eaton-Cummins Endurant. (Photo: Peterbilt)

Truckers who prefer manually clutching and shifting through gearboxes are likely to have a harder time finding a stick shift in their next rig. Fuel efficient, driver-friendly automated manual transmissions like the Eaton-Cummins Endurant are becoming ubiquitous.

Commonly referred to as an AMT. an automated manual transmission is not an oxymoron. The difference between an automatic transmission like most automobiles have and an automated manual is the presence of a clutch. But rather than the driver having to depress the clutch to shift gears, computer controls inside the transmission make the decisions.

They are easier to drive, requiring less effort to move a loaded trailer or work in off-highway vocational pursuits. They use less fuel and cost less to maintain than a manual transmission because clutch cables, linkage, cylinders and manual shifting components need no service.

Their adoption is practically complete in on-highway trucks. For example, Volvo, which introduced its I-shift in 2001, saw take rates in the low single-digit percentages in 2007. Last year, the I-shift accounted for more than 95% of its transmissions. Daimler Truck said AMT sales soar from about 15% in 2012 to more than 90% in 2021.

Companies that don’t make their own automated manuals source them from the joint venture of Eaton Corp. (NYSE: ETN) and leading engine maker Cummins Inc. (NYSE: CMI) The joint venture they created in 2017 has generated more than $2 billion in revenue in the last five years..

The Eaton-Cummins 18-speed heavy-duty automated manual transmission. (Photo: Eaton)

“We were seeing this shift to automated manuals in our heavy-duty market and really an opportunity to partner with Eaton and bring this Endurant transmission into the market,” Jennifer Rumsey, Cummins president and chief operating officer, told FreightWaves. “We’ve seen a lot of success in adoption.”

Even without the Endurant name.

Private branding

Paccar Inc. (NASDAQ: PCAR)  this week revealed new 18-speed transmissions based on the Endurant XD that went on the market last year. The parent of Peterbilt and Kenworth did its own calibrations and software to create the private brand TX-18 and TX-18 Pro that mate with Paccar’s MX11 and MX13 engines. Paccar’s DAVIE4 service tool works on both engines and transmissions.

On a greater scale, Endurant has done the same thing with Cummins’ X-Series engines, starting with a 12-speed for the X-12 engine and expanding to the X-15 Series. With software adjustments and other transmission trim parts like cooler fittings and extra brackets, the joint venture can ship 70 versions of the same transmission to manufacturers.

Just AMTs

Formally called Eaton-Cummins Automated Transmission Technologies, the joint venture makes only what its name says – automated manual transmissions.

Eaton was working on what would be the joint venture’s first product — the 12-speed HD — when talks on working together began. Eaton builds, tests and validates the transmissions. The joint venture designs, manages and sells them.

Ken Rocker joined Eaton’s HD development team in 2015. Today, he is the product manager for the 18-speed AMT.

“Most of us weren’t aware of those goings on,” he said of the JV’s formation. Selling products and making money is the obvious end goal, but the engineer in Rocker looks at an integrated Cummins’ powertrain as being better for customers. “It’s not all about revenue,” he said.

Red-painted Eaton-Cummins branded powertrains are the JV’s most noticeable products. Just as Cummins’ engines are options to practically every OEM-produced engine, the Endurant is there, too.

The 18-speed Eaton-Cummins Endurant XD transmission paired with the Cummins’ X15 Performance Series engine.(Photo: Cummins)

“You can get the Endurant 12-speed in some form at all the major OEMs. Mack, Volvo, International, Peterbilt, Western Star, Freightliner, Kenworth all have our products. Whether it’s a private label or only behind specific engines, we’re behind every nameplate one way or another,” Rocker said.

And it is not just diesel engines. Endurant is now offered for Cummins’ 12-speed natural gas variant. With a Cummins’ natural gas 15-liter engine on sale in China and destined for the U.S. in 2024, can the Endurant be far behind?

“There are other markets around the world and some of the partners we have today that we’re in discussions with about launching the Endurant,” Rumsey said. Cummins’ other joint engine-making ventures are mostly focused on specific regions like China and India.  

‘Integrated powertrain battle’

Eaton dominated the manual transmission market in the 1990s and early 2000s. The switch to automated transmissions called for integrating the engine and the transmission for a bigger chunk of under-the-hood real estate.

“It’s an integrated powertrain battle,” Rocker said. “You picture the engines and transmissions pairing off with one another, becoming larger parts of the vehicle system getting integrated with things like the Bendix Wingman Fusion-type stuff.”

Wingman Fusion gathers input from radar, video, and the brake system to create a highly detailed and accurate data picture. Data from its next-generation radar, camera, and the brake system are fused to each other, constantly gathering, sharing, and confirming information. It is another notable example of dominance in trucking. 

The final holdouts

Eaton-Cummins is now invading the high-torque vocational and severe service end of the market.

“It’s the last heavy-duty market that’s been using manual, and we expect to continue to see increased adoption of the automated manual option,” Rumsey said.

Think loggers in Western Canada, oil field trucks in Texas, and road graders and dump trucks everywhere. There is a certain masculine pride involved with doing-it-yourself shifting. They are the highest-skilled, highest-paid professional drivers.

“They have a lot of good reasons for staying with it,” Rocker said. “It’s more senior drivers, a lot of the heavy haul-type stuff. There is always a bit of emotion or ego involved with relinquishing control to the computer. That’s always going to be a challenge. By their very nature, they were maybe the last ones to convert.”

As these drivers drift into retirement, those following them don’t have the same orientation. They grew up riding in cars and trucks with automatic transmissions. A stick shift is as foreign as a transitory radio.

“The driver pool is shifting toward people that only have driven automated transmissions,” said Hank Johnson, Kenworth’s regional sales manager. “Those heavy-haul companies need to be able to put a driver in a truck he can operate safely. The 18-speed is really the last great holdout.”

Manuals will live on

Though their share will shrink to even lower single digits, manual transmissions will live on for business and personal reasons. Though AMTs are better for the bottom line in everyday use, there are trucks used seasonally, such as in farming. The up-front cost of a manual is cheaper. Why pay up for a truck that will sit unused for six months of the year?

“The beauty of this industry is that every truck is custom ordered.There’s like 9,000 options, so it’s not like we’re transitioning and there’s no more manuals,” Peterbilt spokesman Tim Olson said at a media program introducing Peterbilt’s TX-18.

Eaton still makes them outside the JV, all the way down to 10-speed line haul.  

“It’s going to be cloth seats, no chrome, the cheapest transmission you can buy with the smallest, cheapest engine you can buy because that’s what they’re in the truck market for,” Rocker said. “Those types of things will exist for a long time – I would venture to guess for decades.”

Paccar reveals 18-speed automated manual transmissions for Peterbilt, Kenworth

Cummins reworking its engine families to run on multiple low-carbon fuels

Eaton Cummins JV introduces new automated transmission

Click for more FreightWaves articles by Alan Adler. 


  1. Félix de jesus Guevara Vazquez

    Saludos cordiales como operado quiero opinar sobre estas nuevas transmisiones automatizadas yo doy mi punto de vista y se estoy de acuerdo que son más eficientes y más fácil de operar la unidad pesada pero como operador también dor mi mal reseña porque a pesar de que es nueva tecnología adaptada y nuevas transmisiones construidas tiene sus fallas todavía más que una transmisión manual más porque su funcionamiento alas capacidades de carga no son tan eficientes para las cargas más pesadas aún así siendo carga normales de arrastre no tiene la misma fuerza de torque que una manual y menos la misma sincronización de cambios para mi opinión aún le faltan mucho que mejorar para poder remplazar las transmisiones manuales porque apesar de que son nuevas y según más eficientes en alto de combustible aún se siguen fabricando transmisiones Manueles por preferencias de algunos clientes porque tiene Más tiempo de vida y uso que una automática por más eficiente y nueva tecnología que sea aún Seba segir prefiriendo la transmisión manual por mejor desempeño en las unidad pesada y no tanto por el consumo de combustible pienso yo que asta que no sea al 100% eficiente como una manual no BA remplazar totalmente una transmisión manual

  2. Joseph M. Scott, Jr.

    The only reason sales are up on automated transmissions is because drivers rarely get to have input on what the trucking company buys. You have much more control over a manual transmission truck than an automatic. You can ease the clutch out to inch ahead or back under a trailer. With an auto you get more lurching ahead or slamming back into the trailer. The auto hesitates more as well. Going to pull out on busy roadways, need to get going? Let the clutch out and go in a manual. This Eaton auto I have now? You put your foot down to go and you wait for it to decide what it’s going to do. Sometimes starting on a steep hill it refuses to shift. The only people who think these transmissions are great are people who don’t know any better and people who don’t use them!

  3. Jason

    I wouldn’t buy anything but a full manual transmission and I wouldn’t hire anyone that wanted to drive any type of automatic transmission because it shows there lack of experience and that they don’t have a clue about driving a truck!! AND ILL PUT ANY AMOUNT OF MONEY ON IT THAT I CAN GET BETTER FUEL MILEAGE WITH A MANUAL TRANSMISSION THAN ANY AUTOMATIC OR SEMI-AUTOMATIC TRANSMISSION!!! I have drove every kind of automated transmission that they offer today and NON of them can judge what gear to be in better than me!! Not to mention that these automated transmission are extremely unsafe because almost all of them will go into neutral if the engine shuts off!! So if you have engine issues climbing a mountain and shuts off coming down a mountain you don’t just lose the Jake brake but it stops turning the motor over and stops turning the air compressor and you lose the drag of the engine and now your really screwed because you better get stopped with the air that you have because that’s all you have!!

  4. Ted Wright

    I call BS! I’ve recently been assigned a new truck with an AMT. The damn thing is never in the right gear except on flat ground and even then it up shifts to early and lugs the engine to the point of shaking the dash apart. My brake use has quadrupled. It freewheels on a down grade Unless placed in manual mode it bangs the hell out of the transmission when it shifts. And it uses the clutch every time increasing clutch wear. I’ve been getting close to a million miles out of a clutch disc the old fashioned way. Ain’t gonna happen now. An associate of mine tells me the fleet at his employer is is experiencing transmission failure at 200000 miles across the fleet with these POS transmissions. And I can see why add that to the constant smog codes leaving me parked for up to 2 weeks without pay. Makes these new trucks a total piece of crap.

    1. steve

      that is the Big Globalist plan more money and control for them less for the Sheeple.wait if you already haven’t experienced this,but try rocking that AT out of a pot whole good luck won’t happen call a toe truck

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Alan Adler

Alan Adler is an award-winning journalist who worked for The Associated Press and the Detroit Free Press. He also spent two decades in domestic and international media relations and executive communications with General Motors.