There's now a wide array of advanced components to consider when spec'ing a construction truck. Getting buckets of attention are automatic and automated manual transmissions as well as other key spec items.
Lou Gilbert, director of North American marketing for Allison Transmission, calls the manufacturer's Rugged Duty series the “ideal collection of transmissions for the construction segment.” He says these 12 fully automatic units are offered with 5 or 6 spds. and wide and close ratios.
Gilbert advises that a new feature called “2nd Reverse” will be available by mid-year on 4700 and 4800 RDS transmissions. “This new feature offers a second ‘deep reverse’ in addition to the standard reverse to provide greater control and engine braking during operation on steep grades.”
He says 2nd Reverse will also “enable more maneuverability when operating in confined spaces. When a vehicle is in 2nd Reverse, it will have a slow creep capability with high engine speeds. With a mechanical ratio of 17.12:1, it will have an effective torque converter multiplied ratio up to 32.5:1.”
Shane Groner, Eaton's product planning manager-North America, says there are three new models in the company's “two-pedal” UltraShift Plus automated manual line that are specifically designed for the construction market.
“The first model is the Vocational Multipurpose featuring an overall ratio of 36:1, which is ideally suited for a multitude of construction applications such as cement mixers,” he says. “The second is the Vocational Construction, which features an overall ratio of 20:1 and is designed to operate successfully in applications such as dump trucks. The third is the Vocational Extreme Performance, which features a 20:1 overall ratio and is ideal for high performance applications such as steep grades or heavy loads.”
“Considering the new lower-emissions engine changes, it is time to reconsider different axle ratios to maximize performance and fuel economy,” advises Steve Slesinski, director of product management for Dana's Commercial Vehicle Products Group.
“Axle reliability with Dana's newer products has improved when operating in abusive applications compared with previous products,” he continues. “Dana also offers extended protection programs for fleets that intend to keep their vehicles longer than the standard warranty period.”
Slesinski recommends using driver-controlled wheel-differential locks “to maximize mobility for off-highway conditions and avoid downtime associated with towing vehicles at the job site.”
According to ArvinMeritor, fleets should avoid “under-spec'ing” major components and in particular should seek to hit the “sweet spot” for the most efficient range of the engine chosen. “For optimum performance of a particular engine, a balance between axle ratio and transmission performance will have a direct effect on several factors, including fuel economy. Make sure as well that tire size is spec'd in coordination with engine torque, axle ratio and the speed at which the vehicle will be driven.”