Waste Haul Transport Maintenance Part 3: Is Air Suspension Best?

In Part 1 of this series on waste haul transport maintenance, the author examined tires and how to get the most from them.  Part 2 explored developments in refuse truck brakes.  This final installment takes a look at the role suspension designs have in increasing service intervals and improving performance and safety. Fleets are looking for suspension designs that are more road-friendly, Langton says. “We are seeing more interest in air suspensions since they not only offer the better ride that is being demanded by the drivers, but [also] help to eliminate the wheel hop that tears up the road.” He mentions the Link Air Link tandem drive suspension, a unique combination of an air suspension with walking beam, as an example. “This design helps to maintain equal pressure on the ground by using the walking beam while still damping the driver and chassis from the road through use of air springs.” [text_ad] Fleets are also looking at costs. Ben Langton, heavy vocational sales manager for Link Manufacturing Ltd., believes they need to look at cost-of-ownership as opposed to purchase price. “Spending a little more money up front can result in decreased service costs and higher resale value than less expensive options,” he says. For example, he adds, although the Air Link is a premium suspension product, it provides benefits in terms of cargo capacity (up to 200 pounds lighter than other vocational suspensions), reduced downtime for maintenance with long-life polyurethane bushings, and improved driver comfort (which results in fewer driver injuries and lower insurance costs). An air suspension offers benefits to the driver as well as the road, and drivers like products and features that make their lives easier. Air suspensions protect the drivers from road damage that has already occurred and helps to prevent damage to new roads. “It is an indirect concern,” concludes Langton. Not everyone agrees that air suspension is the best choice in this industry. Mack’s refuse product manager Curtis Dorwart considers it the “least popular in refuse, because it’s susceptible to puncture.” Of the three types of suspensions (air, rubber block, and spring), he says Mack’s mRIDE spring suspension provides the best side-to-side articulation and constant ground contact for all wheels, providing traction “in loose stuff” at a landfill. The mRIDE is a six-rod spring suspension with Mack ductile iron axle housings and Mack C150/151 series axle carriers. Its spring leaf design and V-shaped torque rods ensure stability by efficiently transmitting forces into the truck’s frame, according to Mack. Shock absorbers in combination with rubber and steel shock towers also improve ride and handling. “The addition of shock absorbers dampens the reaction of the suspension while parabolic springs bring flexibility for an easier ride in both loaded and unloaded conditions,” says Dorwart. The mRIDE offers greater ground clearance over difficult terrain due to the use of spring leaves over four separate rubber block pads. Lighter than camelback spring suspensions, it delivers increased stability for a smoother ride. Driver comfort was foremost in its design. Because it’s lighter, the mRIDE allows trucks to haul heavier loads with more even weight distribution. “The mRIDE is also virtually maintenance free,” says Dorwart. “The extremely stable Mack mRIDE has real benefits for the refuse market, such as a high driveline position and excellent traction.” While technological developments in tires, brakes and suspensions are making refuse collection more efficient, cost-effective, and safer, there’s no question that regular maintenance, prudent selection, and proper care continue to play a pivotal role in extending the life of equipment for this demanding industry.