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Learn How 16-speeds + Small-Step Technology = Maximum Fuel Economy.

Heightened level of collaboration results in new ‘small step’ automated transmission

In a never-ending quest to improve efficiencies, today’s truck fleets are demanding more from their vehicle and component manufacturers. The low-hanging fruit has already been thoroughly picked over, and carriers are now looking to their suppliers to squeeze more efficiency out of existing products, or come up with new ones that can drive down costs and improve productivity. It’s no small order.

ultraShiftPlus As a result of these demands, manufacturers such as Eaton are working more closely than ever with their commercial vehicle manufacturing partners to develop products that will bring further value to their fleet customers. One example of this heightened level of collaboration is the new UltraShift PLUS LSE 16-speed automated mechanical transmission.  built with vehicle partner Navistar, manufacturer of International branded trucks. The overdrive transmission was designed for optimum performance in Navistar’s vehicles, and will be offered exclusively in International trucks powered by the MaxxForce® 13 and Cummins ISX engines.
The benefits of this arrangement with Navistar quickly became apparently when the LSE project was launched.

“Working together enables our engineering and technical teams to very openly and freely generate ideas and innovate together, and still protect the ingenuity that makes both companies successful long-term,” said Shane Groner, formerly the Eaton North American Product Planning Manager, now Eaton Account Director for Navistar.

Groner was involved in the project from the start, having discovered ways while “skunk-working” (engineering talk for ‘fiddling with’) an UltraShift PLUS transmission deployed with a major U.S. fleet to improve fuel economy by making alterations to the transmission that complemented the unique attributes of Navistar’s 13-liter MaxxForce engine. So impressed was the fleet, that they urged Eaton to commercialize a redesigned transmission built specifically for use in Navistar products.

When the LSE project began, officials from Navistar and Eaton agreed an unprecedented level of collaboration would be required to truly optimize the transmission’s performance with the MaxxForce engine. This led to candid conversations about things like fuel mapping and the disclosure of other trade secrets, in the interest of building the best possible product for the customer.

The result of all this collaboration was the birth of the UltraShift PLUS LSE (Line-haul Small step Efficiency) transmission, configured for optimum performance with Navistar products, specifically the MaxxForce 13 and the Cummins ISX15 engines installed in International trucks. Real-world testing has shown fuel economy improvements of 2-4%, thanks largely to the short 17-18% step between shifts. Eaton calls this Small Step Technology and the small step allows for quick, precise shifting, which is often completely seamless to the driver. The previous industry standard was a 28% step - or 400 rpm, double that of the LSE - between gears. Because the UltraShift PLUS LSE can shift so rapidly, the engine remains in its fuel economy “sweet spot” longer. The development, Groner said, is nothing short of revolutionary.

“This is the only small step direct drive product in the market today. It allows you to stay in that sweet spot all the time,” he said. “We not only ensure that top gear is in the right spot, but that all the shifts we make are getting there; that they all fall into that engine sweet spot.. Even when we’re making a shift.”

Anyone who’s driven a truck knows that keeping the engine in its sweet spot as long as possible is the key to maximizing fuel efficiency. And the LSE employs more than just Small Step Technology to improve fuel mileage. The controls were also adjusted, based on the requirements of Navistar vehicles.

“The controls strategy we’ve had for years with an overdrive transmission and a standard axle was to just get it in top gear and hold it as long as you can,” Groner said. “With automation, we can do things that ensure we hold the correct gear position all the time.”

Drivers who’ve used the LSE transmission have marveled at how smooth the shifts are; in some cases, they’re barely noticeable.

“Those shifts are so quick and short,” Groner reiterated.

Also contributing to the drivability of the LSE is the electronic clutch actuator (ECA), which is now used across the entire line of UltraShift PLUS transmissions.

“The electronic clutch actuator is the heart of the UltraShift PLUS,” Groner said. “What the ECA does, is really enables us to make shifts at will. Whenever we need to, we can open that clutch, disconnect from the engine, make a shift and re-engage. So we can do performance shifts and we can skip-shift very readily.”

The ECA also allows operators to “creep” the vehicle at extremely low rpms, making backing and coupling to trailers a breeze.

The UltraShift PLUS LSE configured for the MaxxForce 13 engine entered production in April, and in July a second version was added, designed for use with the Cummins ISX15 in International trucks.

“The transmission is exclusive to Navistar, but it’s available on both engines,” Groner said. “The benefits are the same, but the calibrations are slightly different.”