Some paver suppliers also prefer polyurethane pads. "From an engineering perspective, we prefer the poly pads over the rubber because the poly pads tend to have lower friction factors," says Kevin Klein, vice president of engineering/research and development, GOMACO. "When our types of machines are making steering maneuvers, it is better to have some slippage occur between the ground and the track pads so that less loading is transmitted up through other machine components."
SPECIAL REPORT Keep road projects on track Bolt-on polyurethane track pads that mount over the triple grousers — such as these from BLS Enterprises — can save a lot of labor. Cut undercarriage costs on pavers and milling machines By Curt Bennink M uch of the undercar- ment manager for milling products be more difficult to operate,” says riage-related owning at Volvo. “That makes the track chain Dennis Clausen, director of training, and operating costs a little bit longer, so you have to take GOMACO Corp. for pavers and milling up the slack. If there are 30 pins “Over-tightening is always machines are driven and bushings and you take .5mm wrong,” agrees Guido Bottin, vice by your maintenance practices. As wear on each pin, it would be 15mm, president of operations, Berco. “It with most tracked equipment, a little which is over half an inch.” leads to accelerated wear of the com- attention goes a long way. While periodic adjustment of ponents (pins, bushings and sprock- Track tension is perhaps the larg- track tension is needed, improper ets) and can cause breakages, espe- est cost driver. Adjustment natu- adjustment can do more harm than cially in the steel chains. On the rally gets looser with wear. “Most of good. “Excessive track tension can other side, running with a loose your wear comes from internal pin cause excessive wear not only on undercarriage may lead to detrack- and bushing wear, which you really the track components, but also on ing of the chains with possible dam- can’t see,” says Rob Hannan, seg- the drive system as the track will age to the system.” 68 asphalt contractor • www.asphalt.com • December 2009 SPECIAL REPORT Advice for hours for heavy-duty use, or after machine is loaded — up to double managing tension the first 100 hours for moderate to compared to the unloaded condi- Every manufacturer recommends light-duty use. “Additional checks tion,” says Bottin. “If not properly checking track tension more or less should occur every other 200 to 250 tensioned, slippages of the under- frequently according to the load additional hours of usage,” he adds. carriage are possible and have to be conditions, Bottin notes. For new More frequent track tension avoided.” machines with bolt-on shoes (steel checks may be required for pav- GOMACO Corp. recommends only or rubberized), Berco recom- ers due to the heavy loads they can checking tension weekly on its larger mends checking both tension and carry. “The operating weight on pav- pavers. (Smaller models have auto- tightness of the bolt after the first 50 ers changes dramatically when the matic tensioning.) “If the track is too Positives of Polyurethane the poly pads over the rubber because the poly pads tend to have lower friction factors,” says Kevin Klein, Polyurethane track pads are quickly becoming the
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