DETROIT. As trucking continues to place new demands on the vehicles it uses to haul freight, suppliers are changing their product offerings to keep up. According to ArvinMeritor, one key component seeing such change is the driveline-- often overlooked but critical to vehicle performance.
At a news conference held at ArvinMeritor’s Research, Development, and Validation center outside Detroit, company executives explained that ongoing efforts to raise federal weight limits on trucks as well as to reduce overall vehicle weight along with the rising needs of the medium-duty segment are all factors behind several new driveline initiatives it is launching.
“Drivelines are at once very simple yet very complex components,” said Karl Mayer, ArvinMeritor’s director-- product line management for drivelines. “They are very important in terms of vehicle reliability. It’s one of those components that often goes largely unnoticed but is oftentimes very critical to vehicle uptime and operation.”
For starters, ArvinMeritor will expand its Permalube (RPL) series driveline by adding a new model, RPL 32, designed for trucks hauling increased gross combination weights (GCWs) of 97,000 lbs or more. “This model would come with faster ratios as well,” Mayer said.
This move comes in response to initiatives to raise the federal weight limits for commercial trucks. Most notable is the Safe and Efficient Transportation Act or “SETA” bill (H.R. 1799 in the House and S. 3705 in the Senate). This measure would permit all states to set interstate weight limits of up to 97,000 lbs for trucks equipped with six axles instead of the typical five.
Mayer also noted the company plans to add a new mode to its Meritor Extended Lube (MXL) driveline series for medium-duty trucks. The aim here is to provide beefier, longer-lasting components for a segment of trucks that is being worked harder than in the past.
ArvinMeritor is also looking at ways to drive weight out of its driveline components help fleets offset weight being added by emission-control technology. “Our target is to slice 50 to 60 lbs out of our products” without compromising durability and reliability,” he said.
Part of that weight-reduction effort will potentially include using aluminum in constructing some driveline components. However, doubts remain over that material’s ability to withstand the long-term stress drivelines are subjected to, Mayer noted. Also on the table will be designing “one piece drivelines” that would reduce weight via a reduction in parts.
“The big challenge is fatigue life,” said Anthony Lentini, ArvinMeritor’s principal engineer for drivelines. “Today we are welding steel to steel. If you add another material in there, like aluminum, how does that affect the weld strength over the life of the driveline? We determined composite materials were not practical in terms of either cost or durability – and durability is really the big issue today in the world of trucking.”
