NASHVILLE. As truck manufacturers turn to “downspeeding” as a means of getting every fraction of an mpg from heavy-duty vehicles, the focus has been on optimized engines and transmissions. But at the Technology & Maintenance Council Annual Meeting and Transportation Technology Exhibition here this week, Dana Holding Corp. will emphasize the critical role axles and driveshafts play in handling the high-torque stresses of low-rpm highway operation.
Dana now offers axle ratios compatible with all seven configurations of the newly enhanced SmartAdvantage powertrain, a joint collaboration between Eaton and Cummins. These configurations include the original small-step overdrive transmission and a new direct-drive option that delivers exceptional fuel economy in less-than-truckload and regional linehaul commercial vehicles with target cruise speeds of 62 mph and below, Dana officials explained in a pre-TMC press conference Sunday.
Together with Cummins and Eaton, Dana has engineered the fastest, lightest, and most efficient drivetrain to help fleets maximize the benefits of engine downspeedingby creating a durable system that manages dynamic challenges resulting from readily available higher torque with less axle reduction, according to the company. Dana’s system includes the Spicer AdvanTEK 40 155 Series tandem axle—offering the industry’s narrowest ratio steps, from 2.26:1 to 2.79:1—along with the SPL 350 driveshaft and SPL 250 inter-axle shaft, which are proven to be the most robust and reliable in their class.
“The benefits of engine downspeeding are undeniable, and we are partnering with industry leaders to advance this efficiency-boosting technology,” said Mark Wallace, executive vice president of Dana and group president of Dana On-Highway Driveline Technologies. “Our joint collaboration with Cummins and Eaton allows Dana to take a comprehensive systems approach, examining the integration of all components throughout the vehicle in an effort to fully optimize performance and make further drivetrain enhancements.”
Dana’s Spicer AdvanTEK 40 155 Series tandem axle supports the SmartAdvantage powertrain and offers a combination of technologies that can enable an engine at highway cruise speed to run up to 200 rpm lower than alternative powertrain systems, while still reducing weight and increasing axle efficiency. The tandem axle’s full selection of downspeeding ratios and options for a variety of Class 8 applications are now available at most OEM truck brands including Navistar, Kenworth, Peterbilt, and Volvo.
Dana also announced a new driveshaft specifically engineered to further support engine downspeeding. Dana’s next-generation driveshaft weighs 30 pounds less than existing products and is tailored to address the specific torque-management strategies of individual commercial-vehicle manufacturers.
Engineered with fewer components, this next-generation driveshaft offers a simplified installation process to reduce assembly costs for original-equipment manufacturers (OEMs) and improve ease of maintenance for truck owners.
Performance and vehicle dynamics are improved with reduced noise, vibration, and harshness levels, which can also extend component life. Available now for pre-production evaluation by OEMs, Dana’s latest innovation is designed for severe-duty, long-haul applications on high-efficiency Class 8 trucks. This driveshaft is ready for powertrains of the future that will be engineered for further engine downspeeding—enabling an axle ratio lower than 2.26:1, which is the fastest ratio on the market today.
“Engine downspeeding is not a one-size-fits-all solution. Each OEM implements this efficiency-boosting strategy in its own way, resulting in very specific torque-handling requirements,” Wallace said. “This next-generation driveshaft ;is the result of our continuous drive to deliver flexible solutions to meet each customer’s unique needs while further reducing weight and improving efficiency in our products.”
More information about Dana's ;downspeeding package for commercial vehicles is available here.