Eaton Fuller Lightning: Addition By Subtraction

Doing away with the front box/back box tradition that’s been the company’s trademark since 1952, Eaton Corp. has rolled out the first product of an all-new heavy-duty transmission line it calls the Lightning Series. Available in July as a fleet-oriented 10-speed rated at 1650 pound feet of torque (the FRLO-16410C-T2), the Eaton Fuller Lightning 10-speed really does break new ground-a single case, integrated oil cooler, no exposed air lines, and on-board electronics that make this manual as close to automated as you could get.

The Lightning is lighter, shorter by about four inches, and, with 40% fewer parts, it’s simpler than a conventional model of the same capacity. The Eaton Fuller Lightning cuts weight by 120 pounds compared to the current Super 10, in part because the new design has a single integrated gear package with main and auxiliary countershafts sharing the same axial centerline and support bearings.

The Lightning’s main selling feature may well be its more driver-friendly nature. It’s a five-hole design on a single shift rail, with automatic range change and an electric splitter button. The non-repeat pattern means fewer shifts, and there’s a much shorter throw. Splitter performance is much improved over current transmission models, and you get Top 2 automated shifting between 9th and 10th gears as standard equipment. Later in the year, there will be optional engine brake and cruise controls on the shift knob.

A key component here is electronics. The Eaton-made electronic control unit (ECU) is now an integral part of the transmission (with resident software of course) instead of in the engine’s ECU. It communicates via a J1939 datalink (the Lightning demands an engine with that capability). The computer will optimize split shifts because it’s constantly monitoring factors such as engine speed, throttle input, and road speed, and how quickly the truck is slowing down. It automatically adjusts the shift logic to adapt to the conditions-even to weather/temperature. The Lightning’s electronics will even intervene to limit damage that an inexperienced or inattentive driver can do. To prevent starting off in too high a gear, for example, it will tell the engine to reduce torque output in such situations.

In my two preliminary drives, the Lightning 10-speed almost seems to want to shift itself. It has a lighter and more precise shift feel, and, combined with the short lever throws, it lets you make shifts faster. As well, it’s quieter because it features the extra precision of 100% helical instead of spur-cut gears (they also last longer).

There are other points not to go unnoticed. The oil cooler-really an oil-to-water heat exchanger-is integrated inside the box (not an extra-cost option), protected from road debris. It uses engine coolant, not outside air, and also eliminates the lube pump. It’s immersed in the oil bath, with engine coolant flowing through it to remove heat from the lube and return it to the radiator. It can even warm the lube in very cold weather, taking some of the stiffness out of the oil before shifting begins. Both the mainshaft and output shaft are hollow, and oil is distributed under pressure through them to lubricate bearings from the inside out.

Damage-prone external air lines and fittings are eliminated because the air system is integrated into the ECU and transmission case, and the splitter button is electric.

PTO offerings bring two six-bolt openings (right side, left side) and two countershaft-driven rear-mounts. Lightning-compatible PTOs are necessary.

Standard warranty coverage for the Lightning 10-speed is five years/750,000 miles in approved applications with use of an Eaton-approved synthetic lubricant. Preliminary pricing information suggests the new gearbox will cost a few hundred dollars more than a Super 10 Top 2-which will be phased out, incidentally, over the next six to 12 months.

Jeff Romig, Eaton’s manager of worldwide product planning and Lightning program manager, acknowledges that it may be five years before we see “performance” versions of the Lightning, namely 13- and 18-speed models, although the hardware development for “much higher torque” is well underway. Expect 1450- and 1550-pound feet models by the end of the year.

Sooner than that, there will be a non-electronic base model of the Lightning 10-speed for North America.