Paccar transmission completes integrated powertrain

MT. VERNON, Wash. – Paccar has rounded out its integrated powertrain with the introduction of its own 12-speed automated transmission, which it’s billing as the lightest in the industry.

The new Paccar transmission was optimized to be mated to the Paccar MX engine, with a clean sheet design, which Paccar Powertrain officials said resulted in several advantages.

The new Paccar transmission

“This transmission is a clean sheet design, which works seamlessly with MX engines and Paccar axles,” said Landon Sproull, Paccar vice-president for powertrain, at a press launch here Tuesday.

Unlike automated manual transmissions, which are built from the foundation of a manual gearbox with electronics installed to handle the shifting, the Paccar transmission was built from the start to be a pure automated transmission, Sproull emphasized. Today, 70% of Kenworth and Peterbilt truck buyers are spec’ing automated transmissions in linehaul applications.

This is expected to increase to 90% by 2020, added Mike Dozier, Kenworth general manager and Paccar vice-president.

“This is the new normal for linehaul customers,” he said. The introduction of the Eaton Fuller Advantage series automated manual transmission has helped drive the automated transmission adoption rate at Paccar from 30% in 2013 to 70% this year.

Dozier attributed this growth to: the excellent reliability and driveability of the Advantage series; the benefits fleets have seen from a fuel economy and driver recruitment standpoint; and the fact drivers themselves have embraced the latest generation automated manuals. So, it’s no surprise Paccar teamed with Eaton to develop the proprietary transmission.

Paccar engineers worked alongside those from Eaton to design the transmission, incorporating some of the strongest attributes of the Eaton product, such as its precision lubrication system and neutral coast. But because it was a clean slate design, they were also able to find ways to improve it, including shaving more than 100 lbs from its weight. It also offers a 750,000-mile oil change interval – the longest in the industry – and boasts a B10 life of 1.2 million miles.

Sproull said the new transmission also offers the deepest reverse gear ratio available for slow speed maneuvering. It also offers predictive cruise, which uses GPS mapping to assist drivers with gear selection while in cruise control. This can deliver up to a 1.5% fuel economy improvement, and reduce shifting by as much as 20%, by taking advantage of momentum to reduce fuel consumption on hilly terrain.

The shifter has been integrated with the engine brake controls and mounted on the steering column. Spec’ing a complete Paccar powertrain – the MX engine with Paccar transmission and axles – can save a customer nearly 400 lbs in weight, noted Kyle Quinn, Peterbilt general manager and Paccar senior vice-president.

The transmission has been field tested with several fleets and in a powertrain test cell at the Paccar Technical Center.

The Paccar transmission will be purchased through Eaton Cummins Automated Transmission Technologies, a joint venture recently formed between the transmission and engine manufacturer. They’ll be built at an Eaton plant in Mexico and available in Peterbilt and Kenworth trucks beginning this October. The transmission is approved for linehaul applications of up to 110,000 lbs gross vehicle weight, and compatible with engine ratings of up to 510 hp and 1,850 lb.-ft. of torque.

Following the unveiling of the Paccar transmission, Kenworth and Peterbilt trucks with the fully integrated powertrain were made available for test drives. We’ll have a full report later this week.


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James Menzies is editor of Today's Trucking. He has been covering the Canadian trucking industry for more than 20 years and holds a CDL. Reach him at or follow him on Twitter at @JamesMenzies.

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