CCJ

February 2018

Fleet Management News & Business Info | Commercial Carrier Journal

Issue link: http://read.dmtmag.com/i/936627

Contents of this Issue

Navigation

Page 28 of 67

commercial carrier journal | february 2018 27 Purpose-built Lightweight Endurant was born to be automated BY JASON CANNON F ollowing three years of develop- ment and barely 90 days aer Eaton and Cummins announced a formal joint powertrain partnership, Eaton's Endurant 12-speed automated transmission was born in September. e first "purpose-built" heavy-duty automated transmission on the mar- ket, Endurant and its torque ratings of up to 1,850 lb.-. will be matched with the Cummins X15 engine rated up to 510 hp in some on-highway Paccar tractors. Automated manual transmissions are bred from a manual gearbox. Even though the process of shiing is auto- mated, the shi pattern isn't changed, says Matt Erdmann, Eaton's manager of program management. With a true auto- mated transmission such as the Endur- ant, many conventional design restraints are removed, Erdmann says. Endurant features linear shi rails – a departure from the standard side- ways-shi pattern required of manual transmissions and AMTs. "ere is no 'across' in the pattern," Erdmann says. "You would have to have about three arms to try and shi this manual- ly." Linear shi rails also help optimize the design for speed and reliability since there's no wasted sideways motion. Endurant weighs only 105 pounds – a byproduct of the fact the 12-speed was designed from the ground up as an automated transmission. AMTs still feature many manual components, and to automate a manual transmission, you have to add more features to it. Endurant removes the manual pieces, which al- lowed designers to work around the unit's function rather than its components. e transmission unit also is slim, but the benefits of a redesign aren't isolated to weight and size. e gearbox features an internal electrical system routing for wires and connectors that minimizes exposure and corrosion. ere's little hanging on the outside of the transmission, which improves overall reliability. Eaton field-tested Endurant for more than 2 million equivalent miles. For about 40 miles, I was handed the keys to a 2016 Kenworth that originally rolled off the assembly line with an UltraShi installed. at soon was removed, and that tractor became an Endurant validation truck with more than 40,000 miles logged by the time I jumped into the seat. I've previously driven the Paccar version of this transmission. Developed in conjunction with Eaton, the Paccar Transmission is as smooth of a 12-speed as you can get with an MX engine. e Endurant version is available in Kenworth and Peterbilt tractors spec'd with the Cummins X15 engine. Other than some Paccar MX vs. Cummins optimization fine-tuning, the two units are identical. Like the Paccar variant, the Endurant's shier sits on the steering column and is integrated with the engine brake. At highway speeds, Eaton's new 12-speed performs at levels you'd expect from the company, with add- ed features you may not expect otherwise. From stop, the transmission nimbly skips through gears to bring the truck up to speed before settling into a sequential shi pattern at about ninth gear. A grade sensor inside the transmission judges the terrain and senses the tractor's power needs, aiding in the shi decision-making process and boosting overall efficiency. At low speeds, Endurant's Urge to Move feature allows the truck to creep forward or in reverse without having to feather the accelerator or brake pedal. Urge to Move features four forward speeds that can be selected manually to adjust speeds under heavy traffic condi- tions. Reverse gets two speeds that also can be selected manually. It's powerful, too: Parked on a 15-per- cent grade, I launched my 70,000-gross- pound tractor using only Urge to Move while letting the Hill Start Assist feature prevent me from rolling backward, and it crested the hill easily. In reverse, Urge to Move makes backing and coupling safer by not requiring accelerator input. On the open road, Endurant's 18.8:1 ratio offers a good low-end ratio for fine control at low speeds, and its overdrive ratio provides a good cruise at highway speeds. e 12-speed unit also offers smaller steps for a quicker and smoother shi versus a 10-speed model. On Endurant, Eaton has stretched oil drain intervals to 750,000 miles, about 50 percent longer than its UltraShi Plus. e new unit needs about half as much fluid, and a pressure sensor indicates when the fluid is low and prompts the driver to stop before the unit burns up. Capable down to 1,000 rpm with downshis happening as low as 850 rpm, Endurant strikes a balance between effi- ciency and power and does so with faster and smoother shis. T E S T D R I V E : E A T O N E N D U R A N T 1 2 - S P E E D T R A N S M I S S I O N Eaton expects Endurant to become its go-to gearbox in line-haul applications as manual transmissions lose their grip as the preferred method of changing gears.

Articles in this issue

Archives of this issue

view archives of CCJ - February 2018