Peterbilt has added Off-Road Calibration and Rock-Free Mode for the Paccar TX-18 Pro transmission. This automated gearbox is available in Peterbilt Models 579, 567, 589,389, 367 and 365.

The Paccar TX-18 Pro transmission is paired exclusively with the Paccar MX-11 and MX-13 engines. It is designed to perform in a variety of vocational applications, including heavy haul, dump truck, wreckers and cranes. The combination of the TX-18 Pro transmission and a Paccar MX engine provides up to 1,850 lb.-ft. of torque and is rated up to 140,000 lbs. GCWR.

The Paccar TX-18 Pro transmission features a new secondary mode which comes from the factory with the newly released Off-Road Calibration. Switching between the primary mode and Off-Road Calibration can be done in a matter of seconds using the stalk-mounted shifter. The system learns road terrain and surface conditions and responds automatically for an improved driver experience, according to the company. It minimizes unnecessary shifting and maximizes time in gear in challenging terrain for excellent performance.

Rock-Free Mode is also now standard on the Paccar TX-18 Pro transmission. If off-road conditions impact maneuverability, the Rock-Free Mode can be engaged with the flip of a switch. Once engaged, the transmission can be quickly shifted between Drive and Reverse to Rock-Free, fully enabling the truck and then automatically returning to its default setting.