Yes, Cummins Builds Transmissions - But You Can't Put One In Your Pickup Truck

Cummins is a renowned builder of diesel engines for pickup and semi-trucks, and it's in the latter where you might also find some of its transmissions. While older semi-trucks tended to have manual transmissions, a shift toward automated manuals started to take hold in the early part of the 21st century. Volvo spearheaded this movement by introducing the I-shift automated manual transmission (AMT) in 2001. Initial uptake was slow, with fewer than 10% of all customers opting for the AMT in 2007. By 2021, though, the I-shift accounted for 95% of Volvo's transmission sales. Keen to join in on the action, Cummins teamed up with Eaton in 2017 to offer its own range of AMTs.

The joint venture has led to the creation of several AMTs bearing the Cummins name, with current models split into the Endurant HD and Endurant XD series, with all being far too big to fit into your pickup truck. Cummins' HD transmissions are relatively lightweight and perfect for on-highway use, while the XD transmissions are better suited for more demanding applications. The HD has 12 forward and three reverse gears, while the XD boasts 18 and three, respectively.

In contrast, the most powerful Cummins-powered pickup truck, which sports a 6.7-liter turbo-diesel inline-six, uses a ZF-sourced eight-speed automatic instead. While perfectly capable for a heavy-duty pickup, it's a much smaller and more delicate unit in comparison to the huge AMTs coming out of the Eaton-Cummins joint venture.

The AMTs produced by the Eaton-Cummins joint venture have been perfectly tailored for use in powerful and capable trucks, as can be evidenced by a quick look over the specs and factory-rated capabilities. For example, the XD series can handle up to 605 hp, in addition to a maximum of 1,850 lb-ft of torque. These AMTs are strong enough to handle some of the most powerful semi-truck engines out there, including Cummins' own X12 engine. In terms of heft, the transmissions check in at around 808 pounds, but are rated to work in applications with a max GCW of 166,000 pounds, which is more than you'll ever be able to safely pull with just a pickup truck.

As more and more drivers turn away from stick-shift operations, the AMT is proving hugely popular. It works by doing away with a typical foot-operated clutch; instead, an ECU controls the clutch, with electro-hydraulic operation that automatically engages and disengages the clutch. With up to 18 gears in the Eaton-Cummins transmissions, not having to clutch must be a bonus for drivers, enabling them to focus on other aspects of driving. As of 2022, the Eaton-Cummins collaboration had its sights on expanding specialist applications, such as logging and oil field trucking, whose drivers typically preferred old-school manual trucks and didn't wish to relinquish control. However, the two firms expected that the gradual influx of new drivers into both industries would slowly phase manual transmissions out.