The new Paccar Automated Transmission was designed from the ground up as an automated transmission. Photo: Paccar

The new Paccar Automated Transmission was designed from the ground up as an automated transmission. Photo: Paccar

Paccar introduced the new Paccar Automated Transmission, giving it a complete proprietary and integrated powertrain. Developed with Eaton, it's designed from the ground up as an automated transmission and the company says it is the lightest heavy-duty transmission on the market for several of its medium- and heavy-duty models.

Kenworth and Peterbilt will begin offering the new automated transmission to North American customers in October. Peterbilt will offer the transmission with its Models 579 and 567. It will be paired with the MX-13 engine at first, and will be available with the MX-11 engine in early 2018. The Model 567 can be ordered as a Class 6 straight truck.

The 12-speed, twin countershaft design completes Paccar’s goal of a fully integrated proprietary powertrain. Landon Sproull, Paccar vice president, said the all-new, clean-sheet design is optimized for Paccar MX diesel engines.

“The Paccar Automated Transmission is engineered to work seamlessly with Paccar MX engines and Paccar axles and provide industry-leading performance,” he said. “Together, Paccar Powertrain components deliver superior fuel economy, uptime, and driver satisfaction — top priorities for our customers.”

The Paccar Automated Transmission is designed for line-haul applications up to 110,000 lbs. GVW. It is available for engine ratings up to 510 hp and 1,850 lb.-ft. of torque and features tightly integrated electronic communications with the Paccar MX engine.

Company officials said the transmission offers the best overall gear ratio coverage available, providing excellent low-speed maneuverability, and that the transmission is up to 105 lbs. lighter than comparable transmissions.

A new column-mounted shifter puts gear selection and engine brake controls at the driver’s fingertips for better ergonomics and improved performance.

Kyle Quinn, general manager at Peterbilt, noted that altogether, the Paccar integrated powertrain offers customers 399 lbs. of total vehicle weight savings and 7% total fuel economy savings. The transmission can be spec'd with the Predictive Cruise Control option for maximum fuel efficiency.

Mike Dozier, Kenworth general manager, said the Paccar Automated Transmission will be the standard spec for the T680 Advantage fuel economy-optimized tractor. Already, he noted, 70% of all new Kenworth and Peterbilt trucks are going out the factory door with automated transmissions.

Sproull said Paccar is extremely confident in the design, which has a B10 Life of 1.2 million miles. It has a 750,000-mile oil change interval, which the company says is the longest available for line-haul applications.

A differentiated fluid pressure detection system protects the gears and shafts from low fluid conditions. The cooler-less precision lubrication system has an on-demand function that gets lube oil where it's needed without wasting energy pumping it everywhere else too. The fluid capacity of the system is 60 pints.

Gone from the dashboard is the transmission oil temperature gauge. It's been replaced by a fluid pressure sensor that monitors lubricant level and pressure. If it senses a reduction in oil pressure, it will switch into limp-home mode to prevent internal damage. A pop-up message alerts drivers to the low-pressure condition and urges them to pull over as soon as it's safe to do so.

Other features include a maintenance-free clutch and an internally routed electrical system to maximize durability.

The control module is mounted on the top of the transmission case, and has been designed with an internal encapsulated wiring harness and internal sensors to reduce the possibility of moisture ingress to protect the on-board electronics.

The shift actuators are electrically controlled and pneumatically driven, unlike the motor-driven actuators on many automated manual transmissions.

There’s also a clutch protection system that monitors the temperature of the clutch. In high slippage situations, the driver may see a yellow or red pop-up warning advising of a high-temperature condition. The driver would be advised to cease the current activity and allow the clutch plate to cool. This condition is unlikely to arise under normal conditions, but if the driver was slipping the clutch (in creep mode, for example), friction could cause the surface of the clutch plates to get quite hot. The warning will alert the driver before damage occurs.

Based on their confidence in this system, Paccar is offering a “no burn-up” guarantee. “As long as the driver takes appropriate steps to prevent further damage, we will cover any potential burn-up that may result,” said Kenworth Marketing Director Kurt Swihart in a preview last month for some of the trucking press. “That’s an industry first.”

Editor's note: Story was updated on Aug. 23 to included updated information from Peterbilt about the transmission's availability with medium-duty models.