Fleet Management News & Business Info | Commercial Carrier Journal
Issue link: http://read.dmtmag.com/i/599511
68 commercial carrier journal | november 2015 EquipmEnt: 6x2 AxLES tions on uneven terrain or poor roads because of the potential for lost traction if the drive wheels lose good contact with the pavement, Perry says. "In a worst case, you may have to call a tow truck in to pull a stuck tractor all of 3 feet to get it going again." Fleets with 6x2 experience say the lack of a second powered axle is the biggest hurdle for drivers to overcome. But Phil Braker, chief operating officer for Normal, Ill.-based Nussbaum Trans- portation Services, says a little coaching can help drivers learn to compensate for both bad roads and weather. "You can imagine that transferring that kind of power to a single drive axle can be difficult for drivers to get used to," Braker says. "Coaching the drivers on how to handle the trucks was para- mount for us. A driver has to be smart about where he goes and what he does." Nussbaum runs all 48 contiguous states with 6x2 axles. "We run Min- nesota all day long, and a 6x2 is fine in those conditions as long as the driver is smart about how they drive," Braker says. "We noticed that once all our 6x2 drivers went through one winter, we saw noticeable improvements in traction and towing issues because they learned – sometimes the hard way – where not to go and how to be alert for traction issues like gravel, curbs or uneven roads. Now we even have instances where 6x2 drivers are pulling 6x4 tractors out of bad spots." Truth be told, Braker says, Nuss- baum drivers probably would prefer a 6x4 if given a choice. "We really don't hear much grumbling about 6x2 axles anymore," he says. "The way our driver reward system is set up, fuel economy is the biggest opportunity for them to make bonus money, and there's no cap on that. The better fuel economy they get, the more they make. The 6x2 axle really helps them make those bonuses." Other disadvantages fleet managers should consider when looking at 6x2 drive axles also are related directly to the way power is transmitted to a single drive axle – namely, proper engine torque management and accelerated tire wear. Joseph Phillips, director of fleet maintenance and equipment for Rocky Mount, N.C.-based Eagle Transport Corp., says that both initial and sub- sequent test fleet results with 6x2 axles have delivered significant fuel economy and payload improvements. "The only major downside so far has been acceler- ated tire wear," Phillips says. Eagle is attempting to manage this issue by changing its tread design spec – especially on the non-driven axle. "It is still too early to say for sure, but we are expecting to greatly improve our tire life over our early results," Phillips says. "Un- fortunately, I don't see anything right now that will give us the same tire life we were used to with our 6x4 tractors. But the fuel economy and payload gains offset the tire wear losses we are seeing." Perry says that from a maintenance standpoint, 6x2s are easier on a shop because there are fewer components present in the axle that require attention. "The tradeoff is that you will see acceler- ated tire wear." Braker says Nussbaum found tire wear on its 6x2 trucks boiled down to two issues. "The first was the driver," he says. "We had guys taking off with 6x2s like they still had two drive axles behind them. What you get is a much more ag- gressive launch with all that power and torque channeled into one drive axle." Nussbaum drivers had too much torque going to the ground in low gears. "We had drivers roasting their tires at times," Braker says. "You've really got to talk to the drivers about managing their launches. Slow and smooth is definitely the way to go with a single drive axle." Truck rental and leasing company Ryder System was one of NACFE's partners on its 6x2 test program. Normal, Ill.-based Nussbaum Transportation Services runs all 48 contiguous states with 6x2 axles.