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Eaton’s Cool Solution To Reducing Transmission Weight

Eliminating the oil cooler and using aluminum parts, allowed Eaton to reduce the weight of its Fuller Advantage Series™ transmission by 82 pounds.

Maybe nobody ever thought of eliminating the transmission oil cooler before. Or maybe they did, but didn’t think it could be done. Conventional wisdom, after all, would suggest a transmission needs an oil cooler to keep the oil, well, cool. To prevent overheating and to ensure the protection of the gears and other components which comprise the guts of a transmission.

Fuller Advantage SeriesWith its recently launched Fuller Advantage™ Series transmission, however, Eaton has eliminated the oil cooler in what could be described as one of the most significant advances in manual transmission technology of the past two decades.

Eliminating the oil cooler benefits the end-user in several ways, explained Christopher DeFrancisco, program manager at Eaton.

“Eliminating the transmission cooler reduces weight, decreases system complexity and eliminates the potential for leakage,” he says. 

But to eliminate the oil cooler, Eaton first had to develop a new Precision Lubrication system that could function with less oil in the first place while still providing sufficient lubrication. “The oil delivery system in the Fuller Advantage transmission is dramatically different, so less oil is required (7.5 pints less),” said Jeff Walker, global product manager for manual transmissions with Eaton. “With splash lube systems, the oil has to be filled to a higher level to ensure that the gears and bearings have adequate lubrication considering the operating inclines/grades that can be encountered. The Fuller Advantage Series uses a pump and a system of tubes to distribute the oil so it is less reliant on the fill level.”

Using the Precision Lubrication system in place of the traditional wet sump design, means oil-churning losses that negatively impacted fuel economy have been eliminated.

Eaton has also trimmed significant weight from the Fuller Advantage Series: about 35 pounds through the strategic use of aluminum parts, 40 pounds by eliminating the oil cooler and lines, and another 7 pounds from the 7.5 fewer pints of transmission lube. The 82 pound weight savings, combined with a more efficient design, have combined to improve fuel economy by about 1.9% in fleet testing.

“Our field test trucks operating in customer units continue to provide very positive results, with several trucks running over 8 miles per gallon,” DeFrancisco said.

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The improved efficiency of the Fuller Advantage Series design can, in a typical fleet operation, deliver cost savings of more than $1,100 over an 18-month period, DeFrancisco explained. The new series delivers maintenance savings as well. Eliminating the oil cooler can result in a reduction in downtime and the addition of a sight glass allows technicians to more easily inspect oil levels. These benefits, as well as the weight reduction, can add another $60 in savings over 18 months, DeFrancisco added. “Over a five-year lifecycle, we estimate the Fuller Advantage Series will deliver about $3,600 in total savings,” he said.

The heart of the new Precision Lubrication system - the pump - is based on a proven design, the version already in use on Eaton’s previous manual transmissions, but with an increased capacity.

“The previous generation pump has demonstrated very good reliability for a number of years,” Walker said. “The new pump in the Fuller Advantage has undergone significant testing to ensure it will be reliable. There are no added electronic parts in the lubrication system.”

The Fuller Advantage Series was brought to market in 2013 and has been well received by the industry.

“There has been a broad demand from fleets of various sizes and applications,” Walker said. “We’ve had several fleets that were part of our field test convert existing orders and place significant orders for trucks with the Fuller Advantage based on their experience with the product.”

The conversion of fleets that have first-hand experience with the new product is encouraging. So much so, Eaton has expanded the Fuller Advantage Series to include products beyond the 10-speed manual that was first introduced.

“Our Fuller Advantage Series portfolio includes a 10-speed manual, and integrated solutions such as the Cummins and Eaton SmartAdvantage Powertrain and the PACCAR MX-13 / Eaton Fuller Advantage Powertrain which feature an automated transmission with Small-Step Technology,” Walker said, “and we’re adding Direct Drive and Overdrive versions of the Fuller Advantage automated later this year.”