SKF Supplies New Design Wheel Hub Units for 2004 Dodge Durango

SKF AB (Sweden) has introduced a new bearing design for the front wheel unit hub assemblies used in DaimlerChrysler's 2004 Dodge Durango SUV. The new Durango units are, "just the first of a new breed of performance engineered bearings," said SKF, in a series named X-Tracker®. Designed specifically for light duty truck and SUV front wheel applications, X-Trackers are asymmetric angular contact ball bearing units. In this design, the outer race has a larger diameter and carries more balls than the inner race. The larger bearing pitch diameter not only increases load capacity without significantly altering the hub's envelope dimensions or rotating weight, but also improves the unit's resistance to deflection ("hub stiffness") by 50% over a similar tapered bearing unit. As SUV's aim to become more carlike, chassis and suspension systems are continuing to receive more attention for their contribution to ride, handing and NVH (noise/vibration/harshness). Rapidly escalating wheel and tire size wars among SUV makers have also seen bearing loads increasing exponentially. Because the front wheel outer race carries more load during cornering, the larger pitch diameter aids steering precision handling by virtue of its rigidity. At the same time, the differing pitch diameters reduce NVH by altering the bearing's inherent vibration frequencies. And because they were able to implement it as a ball bearing unit, X-Tracker offers less drag and slightly better fuel economy than a similar tapered bearing unit. By holding the hub face and rotor in position relative to the caliper under cornering and braking, SKF says the X-Tracker hub unit also improves braking responsiveness while reducing front brake wear and warranty costs. Durango X-Tracker front hub units are being manufactured at SKF's U.S. hub unit plant in Glasgow, Kentucky, and are considered part of the 3rd-generation hub unit (HBU3) product line. Glasgow's HBU3 line was expanded and upgraded to accommodate the Durango unit. DaimlerChrysler builds the Durango at its Newark Assembly Plant in Newark, Delaware. While the 2003 Durango was based on the Dodge Dakota truck chassis, the 2004 Durango has a unique chassis which is not yet shared in the DaimlerChrysler family. Car and Driver magazine said about the Durango's suspension: "The cumulative effect of all this gear is a truck that drives more like a big sedan. There's no slack in the steering, the ride is comfortable, and the handling is about as good as it gets for an SUV." When it went on sale in November 2003, Dodge sold over 7,700 units and had a backlog of over 40,000 orders. In January, a stop-sale order on hurt Durango sales as Dodge recalled all 21,000 produced with 3.7 and 4.7 litre engines to fix a problem with throttle cables that could freeze open and cause a, "crash without warning." Even so, dealers sold 8,888 Durangos in January, up 38% over the old model's sales in January 2003.