When the engineers at the Chrysler Group started redesigning the all-new 2004 Dodge Durango, they were looking to not only make it bigger, but also better in several ways. One of the issues going hand in hand with increased weight, was the need to retain efficient rolling and accurate handling. SKF answered the challenge by designing an innovative asymmetrical ball hub bearing unit to replace the standard tapered roller bearing unit. This new design consists of a double row angular contact ball bearing arrangement in which the outboard row is at a higher diameter and contains more balls than the inner row. This unique design increases the bearing’s capacity while improving hub stiffness by 50% over a traditional tapered bearing unit. A stiffer hub provides many benefits. It allows the wheel to run truer during cornering and acceleration. It reduces deflection of the hub face and wheel, which provides better steering, handling and vehicle dynamic behaviour. A stiffer hub also reduces brake wear due to true running of rotors, which helps reduce brake warranty costs. Furthermore, it improves both NVH (noise/vibration/harshness) characteristics and bearing performance. Finally, it allows designers and systems integrators an alternative to a tapered bearing unit that will provide them freedom to improve overall vehicle performance. The SKF asymmetrical ball bearing units will be standard on the front wheels of the Chrysler Group’s all-new 2004 Dodge Durango. This bearing solution is just the first of a new breed of performance engineered hub bearings that SKF has named X-Tracker. The X-Tracker series of bearings employ new designs and advanced processing techniques to bring car-like handling and comfort characteristics to high performance light duty truck and SUV applications. These X-Tracker hubs are manufactured in SKF’s Glasgow, Ky., plant which was expanded and upgraded to include a state-of-the-art HBU3 channel that produces bearings for the all-new Dodge Durango. HBU3 stands for a hub bearing unit, 3rd generation, which includes an inboard mounting flange and outboard hub and wheel studs for tire mounting).