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The automotive industry is continuously striving to reduce vehicle mass by reducing the mass of components including wheel bearings. A typical wheel bearing assembly is mostly steel, including both the wheel and knuckle mounting flanges. Mass optimization of the wheel hub has traditionally been accomplished by reducing the cross-sectional thickness of these components. Recently bearing suppliers have also investigated the use of alternative materials. While bearing component performance is verified through analysis and testing by the supplier, additional effects from system integration and performance over time also need to be comprehended. In a recent new vehicle architecture, the wheel bearing hub flange was reduced to optimize it for low mass. In addition, holes were added for further mass reduction. The design met all the supplier and OEM component level specifications.

This paper will focus whining noise on rear axles applied in mid-size trucks. Vehicle integration changes during development affect directly the gear noise perception, in which it may be intensified. Also, gear material and heat treatment choices for the rear axle need to be done carefully, taking into consideration the integration changes and also the driver usage. A lessons learned collection over the diverse aspects of a rear axle whining noise will be the basis of this paper.

This work aims to summarize in a single form all legal requirements that dictates the minimum safety compliance required by government edicts to any wheel manufacture to have their products available for passenger or light truck vehicle in any country around the world in the year of 2016. It is not intention of this paper compare or discuss the different requirement among the countries but indicate to the manufactures of wheels what legal edicts they need to meet in case they are willing to go overseas to explore the wheel market of other country. Before start designing wheels for passenger or light truck application, any manufacture should be sure about what the government of the new market demands for wheels when installed on vehicle axis or just available as temporary spare. Another objective of this paper is to be a short reference for new automakers to know what to demand from their suppliers of wheels before starting business with them or shipping vehicles to any new market.

Basic driveline configurations offered in mid-size trucks have a standard “open” differential. Open differentials allow smooth cornering, as the outside tire must spin faster on corners as it travels a larger arc, when compared to the inner tire. This system has a main problem when traction is lost, due to slippery roads, different friction coefficients between pavements or even when the axle is submitted to a twist ditch. All of the power goes to the wheel with the least traction and the pickup is stuck. In order to improve traction on these situations, limited slip differentials were developed. A limited-slip differential will prevent excessive power from being allocated just to one wheel, and thereby keeping both wheels in powered rotation. There are several solutions offered in the market, each one presenting different torque transfer capabilities.

The required hand wheel effort the driver inputs into the steering wheel during parking maneuvers is an important design factor for a vehicle, that has a strong influence on the customer's overall perception of steering performance. During the development of a new vehicle, the designer is faced by the challenge of achieving the desired level of steering effort without jeopardizing other handling characteristics, like steering sensitivity and on-center performance. The suspension and steering tuning to achieve the adequate trade-off between these different metrics is especially critical for manual steering systems, which is a very common configuration for emerging market vehicles. In addition, due to communization of architectures, it is common that a vehicle with a manual steering system must share common suspension components and geometric parameters with configurations that have power steering assistance, making this trade-off even more difficult.