Despite decades of supplying and improving upon some of the oldest and most reliable components found on trucks, axle and suspension manufacturers are facing new challenges as new operational demands and technology take hold in trucking.

Conventional truck designs are laser-focused on uptime and fuel economy, requiring lighter designs and even new lubricating fluid metering systems to reduce parasitic horsepower loss due to “churn” at cruising speeds. As with any vehicle system, electronic sensors that can communicate data on an axle’s health in real time are finding their way onto new axles.

And axles are in the spotlight now as new electric vehicle technology takes root in trucking with a new set of unique operational demands.

In fact, Meritor CEO Jay Craig says he’s never seen the trucking industry undergo such rapid change. At the North American Commercial Vehicle Show in Atlanta in September, Meritor announced that it is developing a new portfolio of electric drivetrains to meet these new demands and ensure electric truck customers have the capability and reliability they’ll need.

“We’re also committed to electrification,” Craig said. “We’ve had a lot of interest from OEs on how we can start to work with them to launch demonstrator and production vehicles as well.”

Essentially, Meritor is focusing on integrating an electric motor into the differential carrier. The flexible e-carrier design will be the foundation for various drivetrain configurations, including full electric, hybrid, single, or tandem axles with various options based on application.

Also at NACV, Bosch showcased several future-focused powertrain concepts, including the eCity Truck diesel hybrid system for light commercial vehicles that uses an electric axle. The eAxle is a scalable, modular platform with the motor, power electronics, and transmission forming a single compact unit.

Late last year, Dana announced a Spicer Electrified portfolio of fully integrated motor, control, and e-drive technologies designed to advance electric propulsion systems. Currently in production, the Spicer EV Drive for electric vans manages speed and torque from the e-motor to the wheels. Planned for launch in 2018, Dana’s e-axles for electric transit buses and city delivery vehicles will feature a fully integrated motor and gear box.

In addition, a startup by the name of Hyliion is launching an electric-powered axle for highway tractors, now being tested by three major fleets. Hyliion’s 6X4HE system generates electric power on downgrades or while coasting, and supplies supplemental power during launch and on upgrades.

But even as they work toward designs for an electrified future, axle and suspension makers are still refining and introducing new products to help deal with the issues fleets face today, including the driver shortage, fuel efficiency, vehicle weight, uptime, and more. For instance, Daimler Trucks North America is developing new “taller” tandem drive axles for fuel economy, looking to reduce the rear axle ratio to 2.0x in the future.

Following is a roundup of some of the latest news from axle and suspension manufacturers.

Bosch teases eAxle design, Tesla partnership

Bosch showcased several future-focused powertrain concepts at NACV, including the eCity Truck diesel hybrid system for light commercial vehicles that uses an electric axle. The eAxle is a scalable, modular platform with the motor, power electronics, and transmission forming a single compact unit.

To further reduce fuel consumption, the eCity Truck platform can also seamlessly integrate 48-volt technology. The Bosch boost recuperation system allows for the provision of 48-volt electrical accessories as well as energy recovery, and efficient functions such as start-stop.

According to Bosch, eAxle will be a key component in its development partnership with Teslsa to bring its electric truck to market this year. The eAxles will be paired with a custom-designed fuel cell system – also being developed jointly by Nikola and Bosch – designed to deliver the desired vehicle range.

Dana adds downspeeding ratio option to Spicer AdvanTek 40 axle

Dana has added a new axle ratio for the Spicer AdvanTek 40 tandem axle that helps support engine downspeeding for linehaul trucks. The new axle ratio of 2.47:1 allows truck buyers to fine-tune their driveline specifications for an optimized balance of productivity and fuel efficiency, the company said.

The latest ratio is suited for direct-drive versions of the SmartAdvantage Powertrain from Eaton and Cummins. The configuration is recommended for regional-haul applications in a mix of driving environments.

The SmartAdvantage Powertrain features the Cummins X15 Efficiency Series engine paired with an Eaton Fuller Advantage 10-speed automated manual transmission.  By using engine downspeeding and leveraging the Cummins X15 engine’s low-end torque, many vehicle operators will see a tangible improvement in fuel economy over traditional drivelines, according to Dana.

Ingersoll Axle introduces steer axle, integrated suspension

Ingersoll Axle by Dexter launched its Smart-Steer 2.0 steer axle and Smart-AXL integrated suspension. According to the company, the Smart Steer 2.0 is the first of the company’s newest generation of self-steer axles, designed to be smarter and easier to use. The axles feature a bolt-on steer arm, allowing quick changes in steering angles and reducing repair costs and downtime. It features a slimmer torpress design and has no proportioning valve, which can result in better performance, increased reliability, longer life, and ease of service, according to the company.

The Smart-AXL suspension is a top-mount, integrated suspension system for weight-conscious tandem and tridem applications such as tankers, flatbeds, grain, and livestock haulers. It boasts a capacity of 23,000 pounds with ride heights from 14 to 19 inches. The suspension design results in a smooth ride, better performance, and more durability, according to Ingersoll Axle.

Hendrickson OptiMaax 6x2 liftable axle for Cascadia

Hendrickson Truck Commercial Vehicle Systems partnered with Freightliner Trucks to offer the OptiMaax 6x2 liftable forward tandem axle on the new Cascadia tractor.

According to Hendrickson, the OptiMaax axle can help fleet customers optimize the movement of variable loads, as well as assist carriers with diminishing loads. Examples include bulk haulers and delivery vehicles that may have empty backhauls after carrying items such as groceries, livestock, beverages, and fuel. It also helps fleets that focus on weight reduction and those who want to improve fuel efficiency.

Controls sense the load capacity and automatically lift or lower the axle without relying on the driver, maximizing time with a raised axle and enhancing traction. The OptiMaax 6x2 design is compatible with drum and air disc brakes and is unique because the axle is fully welded, not bolted, adding strength and durability, according to Hendrickson.

Hutchens tank container chassis suspensions

The Lite Weight 109 series of Hutchens suspensions are designed to meet the needs of tank container fleets with a maintenance-free design, according to the company. The Model 9700-TWS-109 suspension features a Huck fastening system for the rocker/hanger assembly and lightweight, fabricated hangers with ½-inch wear pads and drainage holes to reduce wear at all spring contact points and increase service life and a “Million-Mile” rocker bushing. Torque arm screws allow for easy adjustment for suspension alignment.

Mack adds automatic standby for 6x2 liftable axle

Mack Trucks added an Automatic Standby Mode option for its 6x2 liftable pusher axle available on Pinnacle highway models. With Automatic Standby Mode, drivers no longer need to manually activate standby mode, which simplifies operation. When the ignition is off, Automatic Standby equalizes the suspension pressure, preventing the rear axle from being overloaded. The driver doesn’t need to initiate standby or remember the button sequence to put it into standby.

The 6x2 with liftable pusher axle is capable of determining payload by using sensors in the rear suspension and either lifting or lowering the foremost rear axle. When an empty load is detected, the axle lifts, allowing the tractor to operate as a 4x2 for less drag, better fuel efficiency and reduced tire wear, which helps lower maintenance costs.

Mack has also added rear air disc brakes as an option to its 6x2 liftable pusher axle.

Meritor outlines integrated axle-electric motor system

Meritor announced at the NACV Show in September that it is focusing on integrating an electric motor into the differential carrier on a new drivetrain for electric trucks. The flexible e-carrier design will be the foundation for various drivetrain configurations, including full electric, hybrid, single, or tandem axles with various options based on application.

Because the electric motor is integrated into the axle, space is freed up for batteries and other electrical components, offering easier packaging and installation and a safer, more protected location inside the frame rails to mount the batteries. The design also eliminates cost and weight associated with a driveline and mounting a remote motor with brackets.

Other near-term electrified solutions under development include an integrated two-speed electric carrier platform for mounting on existing axle platforms, as well as a 13Xe rigid axle, capable of 200 kilowatts of continuous power and featuring customizable gearing to cover different applications.

Paccar adds wide-track vocational steer axle

Paccar is adding a new proprietary front axle for its Kenworth and Peterbilt vehicles, designed for demanding vocational applications such as refuse, construction, and heavy-haul, featuring a combination of weight savings technology and durability. Available with ratings of 20,000 or 22,000 pounds, it uses an innovative tapered kingpin roller bearing, which simplifies the design and delivers enhanced steering efficiency. The Paccar front axle offers steering angles up to 50 degrees and has a five-year or 750,000 mile warranty.

Reyco Granning LiftMaster lift axle suspension

The Reyco Granning LiftMaster ALAP-13 (PS) and (NS) suspensions take the place of the company’s L132 (steerable) and L130 (non-steerable) air spring lift axle suspension systems and are designed for the heavy-duty, Class 7 and 8 market. The suspensions are rated at 13,500 lbs and are 75 lbs. lighter in the steerable version and 100 lbs. lighter in the non-steerable version compared to competitive models, the company says. 

LiftMaster eliminates cavitation often found with stabilizer shocks through the use of a gas-charged, monotube steer damper. The nitrogen-charged stabilizer shock also eliminates the need for coil springs, and the large diameter piston increases damping force without increased heat generation. The LiftMaster also enhances driver safety by having the automatic lift in reverse feature, permitting the driver to safely back the truck without having to remember to lift the suspension in order to prevent damage.

Ridewell self-steer auxiliary suspension updated for I-Beam axle integration

Ridewell Suspensions updated the RSS-236 self-steer auxiliary truck suspension for I-beam axle integration. First released in 1997, the RSS-236 suspension has been updated for lighter weight and lower maintenance. The parallelogram design allows customers to integrate an I-beam axle into the suspension.

The RSS-2361000 offers an adjustable frame width and low-maintenance polyurethane bushings. An integrated air tank kit is also available for the suspension.

The RSS-2361000 suspension is designed for single wheel application (no duals). The suspension is rated for a 13,500-pound capacity; however, the tire and wheel combination used may dictate the suspension’s gross axle weight rating.

SAF-Holland LSZ Steerable Axle

SAF-Holland introduced its large-capacity 20,000-pound Neway LSZ auxiliary steerable lift axle suspension, designed to be more compact with increased lift speed and improved ride performance.

With an 18.3-inch package size, the LSZ’s design is up to 8 inches shorter than comparable lift axles, according to SAF-Holland, allowing it to fit into tighter spaces and providing extra frame rail space for additional equipment. The LSZ on a new truck can reduce the vehicle’s overall wheelbase as well, providing more maneuverability to get in and out of tight spots.

The SuperChamber lift device provides double the lift speed of traditional air springs, according to SAF-Holland, protecting tire life and improving efficiency. The company also says it is more durable than comparable lifts and its strong lift force keeps the axle from bouncing and banging on the chassis, offering more comfort for drivers. The SuperChamber also provides increased protection from road hazards and easier access for servicing.

About the author
Jack Roberts

Jack Roberts

Executive Editor

Jack Roberts is known for reporting on advanced technology, such as intelligent drivetrains and autonomous vehicles. A commercial driver’s license holder, he also does test drives of new equipment and covers topics such as maintenance, fuel economy, vocational and medium-duty trucks and tires.

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