August 22, 2017 6:45 PM, EDT

Paccar Introduces Automated Transmissions

Paccar transmission Paccar

MOUNT VERNON, Wash. — Truck manufacturer Paccar has introduced a proprietary automated transmission that the company said completes its integrated powertrain lineup.

The 12-speed automated transmission will be available in vehicles sold under its Kenworth and Peterbilt brands beginning in October, and promises fuel economy gains and weight savings for its linehaul customers, Paccar executives said during a press event at the company’s Technical Center here.

The transmission is a “clean sheet design,” said Landon Sproull, vice president for powertrain. By that, he meant that the transmission was not adapted from an existing manual transmission; rather, it was developed as an automated transmission and never intended to be a manual unit.

TEST DRIVE: Showcasing optimized fuel economy, performance

The transmission also is the first product to come from Eaton Cummins Automated Transmission Technologies, a joint venture between Eaton, — which makes the current automated transmissions offered in Paccar trucks — and Cummins Inc., the independent engine manufacturer whose diesel engines are available in Paccar trucks.

The launch of the Paccar automated transmission, however, is meant to give customers an integrated package with components designed to work together, said Patrick Dean, chief engineer at Kenworth.

“It is about offering a system that is optimized,” he said. “This is a milestone in our overall integrated powertrain strategy.”

That strategy includes the Paccar MX-13 engine and the company’s proprietary rear drive axle. The combined package delivers up to 7% better fuel economy than a Kenworth T680 or Peterbilt 579 equipped with a pre-2017 MX-13, Eaton Fuller Advantage transmission and Dana rear, Sproull told Transport Topics. The 2017-spec engine, which is compliant with new greenhouse gas emission regulations, is responsible for about 4% of the fuel-economy gains, he told TT, with an additional 1.5% coming from predictive technologies incorporated into the new automated transmission.

Those technologies include predictive cruise control, optimized gear selection (which anticipates which gear a truck should be in depending on road conditions) and predictive neutral coast, which disengages the driveline on slight downhill grades to help save fuel. The cruise control will limit the truck’s speed when neutral coast is engaged so that the truck’s speed will not exceed the cruise control setting, Sproull told TT. He noted that the system has proved most beneficial on roads with a 1-2% grade.

Beyond technology, the unit was developed to withstand harsh conditions, undergoing cold-weather testing in Minnesota and hot–weather testing in Death Valley, said Carl Hergart, director of advanced technology at the Paccar Technical Center. The transmission underwent 2 million miles of on-road testing, in addition to track and developmental testing at the technical center, Dean said.

The transmission is controlled by a stalk mounted on the right side of the steering wheel column and features two reverse gears in addition to the 12 forward gears. It also features a power take-off that offers up to 95 horsepower.


Eaton was closely involved with development of the transmission, but the specs for its performance came from Paccar, said Mike Dozier, general manager for Kenworth, pointing to the transmission’s goal of integrating with the other Paccar components. Dozier also noted that automated transmissions are an increasingly popular choice for fleets, and he credited the Eaton Fuller automated manual unit Paccar has offered in its trucks for delivering “excellent reliability.”

Going forward, he said that automated transmissions are expected to make up 90% of Kenworth and Peterbilt linehaul sales by 2020. “Fleets have turned to automated transmissions to improve fuel economy and attract younger drivers,” he said. “Automated transmissions are the new normal for linehaul customers.”

The Paccar automated transmission has a five-year, 750,000-mile warranty; its oil change interval also is 750,000 miles. The units will be built at Eaton’s factory in San Luis Potosi, Mexico.

Paccar is based in Bellevue, Wash.