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”U” bolts are fixing elements and they are used to clamp an elastic joint. From the past, they still looking as an old design and unfortunately, suspension engineers are not specialists in fasteners and elastic joints. That is why we will show important assumptions and concepts to design and specifications this clamp element “U” bolt and its influence over leaf-springs. Currently, “U” bolt is used to clamp an elastic or elastic-plastic joint of heavy duty suspension, formed by leaf-spring, axle, spring pad, “U” bolt plate. This kind of suspension is typically used to trucks, buses and trailers. We are wondering, which one important assumption that an engineer must be careful when designs a new suspension changing from old designs to an updated technology. We provide a theoretical analysis and a FEA analysis to compare torque efficacy x leaf-spring reactions and what are effects this relationship can cause in a suspension.

The term triple safe is used to identify an air brake system with three separate circuits, two of which are service brake systems of virtually equal effectiveness; the third is a spring parking brake system. The paper reviews the spring parking brake chamber capability and describes a triple-safe air brake system and chambers that have similar service and emergency capacities, and parking capabilities, to meet future requirements of trucks and buses.

TFC/IW, total fuel consumption divided by inertia weight is reported with other engineering variables for recent EPA data for industry passenger cars and truck. TFC/IW is used in comparisons between gasoline and diesel engines, 49 States and California, passenger cars and trucks. The California fuel economy penalty due to more stringent emissions standards is discussed. The relationship between TFC/IW and ton miles per gallon is shown. Special attention is focused on 4 cylinder gasoline powered vehicles in 49 States passenger car fleet. The use of TFC/IW to answer the question, ‘What Changed?’ when comparing the fuel economies of two fleets is described.

An unique bonding mechanism was studied after several instances, where the linings stuck to the brake drums on transit buses, were reported. Evidences suggested that the linings were “glued” to the brake drums surface after wear debris (dust) was turned into “adhesive paste” through complicated thermal and chemical changes. Factors such as the friction materials, environment and service conditions, which could activate and deactivate the lining bonding, were observed and discussed. The prevention measures are proposed.

The SHIFT-MATE is a dashboard mounted computer based device that cues a truck driver to shift more efficiently. Through electronic circuitry, key vehicle parameters are monitored, computed, then via graphic display, instructs the driver when to shift for improved fuel economy. The theory of operation is described in the text.

Dodge wanted to promote the new Dodge Ram 1500 pick-up truck and regain a presence in NASCAR and was looking for a venue that would accommodate this presence. NASCAR launched the NASCAR Craftsman Truck Series (NCTS) in 1995 and Dodge joined the series. This paper will cover the history of Dodge Motorsports Engineering presence in this series. The engineering objective was to develop an organization that would meet the corporate goals. The initial problem was that Dodge hadn't participated in a NASCAR series since 1978 and had no recent experience. The conclusion was that Dodge Motorsports Engineering could be competitive in NASCAR series racing.

The simulation system “Roadrunner” has the ability to compute 3-dimensional vehicle behavior during simulated ABS-stops or Traction Control (TC) operation on a PC based test rig system. This can be done in real-time mode with fast DSP (digital signal processor) boards and an ABS/TC-ECU as a ‘Hardware-in-the-loop’ device (HIL) or off-line (non-real-time), on the PC only. In the off-line-mode, the PC additionally performs the ABS/TC control algorithms. The simulated system includes model equations for chassis and wheel movement, hydraulics and road to tire interactions. A driver model enables the reproduction of standard steering maneuvers.

Due to ever soaring fuel costs and even more stringent emission regulations which require more elaborate technical efforts and unfortunately lead to a negative trend on fuel economy as well, todays and future trucking business is extremely challenged. These facts create an urgent requirement for the engine manufacturer to offer an engine with an optimized cost-benefit-ratio for the trucking business. Mercedes-Benz, as the leader in the European commercial vehicle market - of which e. g. high fuel costs, long maintenance intervals and high engine power-to-weight ratios have always been key characteristics - has developed a new class 8 engine for the US market. The MBE 4000 is a 6 cylinder inline engine in the compact size and low weight category, but due to its displacement of 12,8 liters it offers high performance characteristics like heavier big block engines.

Design of a Cabin Tilting System of heavy trucks, a multi degree of freedom mechanism, is a challenge. Factors like adequate tilting angle, cabin styling, packaging, non interference of tilting system with ride comfort, forces in the system, specifications of the hydraulic system, are all very important for designing the system. Numerous considerations make the design process highly iterative hence longer design time. This paper primarily focuses on Kinematics and Dynamic analysis of the system in ADAMS and validation of system with real time testing results. Intention of this work is to make a parametric ADAMS model and link it to a Knowledge Based Engineering application to facilitate designer to quickly carry out design iterations for reducing development time. The Knowledge Based Engineering software is made using object oriented language called ‘Object Definition Language’ which has been developed using C and C++ software languages.

A new truck type street sweeper has been developed which incorporates some of the sweeping advantages of a three wheeled sweeper (tricycle steer) and the transport advantages of a legal highway truck. It offers major productivity improvements through better operator environment and decrease of nonsweeping time in the operational cycle. It is possible for a small “short line” special purpose vehicle manufacturer to develop, test, and produce such a vehicle and meet Federal regulatory requirements with limited “In house” design and testing facilities. Here this was accomplished through judicious augmentation by outside specialized design and testing organizations.

As a typical parameter of the road-vehicle interface, the road friction potential acts an important factor that governs the vehicle motion states under certain maneuvering input, which makes the prior knowledge of maximum road friction capacity crucial to the vehicle stability control systems. Since the direct measure of the road friction potential is expensive for vehicle active safety system, the evaluation of this variable by cost effective method is becoming a hot issue all these years. A ‘wheel slip based’ maximum road friction coefficient estimation method based on a modified Dugoff tire model for distributed drive electric vehicles is proposed in this paper. It aims to evaluate the road friction potential with vehicle and wheel dynamics analyzing by using standard sensors equipped on production vehicle, and fully take the advantage of distributed EV that the wheel drive torque and rolling speed can be obtained accurately.

THE EFFECTS of deposit power loss are most severe in the constant-speed, constant-load service common to the auxiliary or utility-type engines. This paper describes studies made of this problem. Factors investigated are: mechanism of deposit formation, the effect of deposits on operation, design and maintenance problems, and deposit removal. Since the greatest part of this loss results from decreased air consumption, proper attention to engine design can materially reduce such loss. The new multigraded oils may offer some relief from deposit problems because they form less resinous material. Carbon removal by physical or mechanical means also may be beneficial in some cases. Proper engine application and conscientious maintenance, however, can go a long way toward reducing deposits. The authors also discuss the problem of heavy-duty truck operation and passenger-car service.