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Tapered roller bearings have proven successful in a number of high-volume automatic transaxle designs. Typically, tapered roller bearings are required to carry high loads generated by helical and hypoid gears. To meet the demands of a successful design, a number of factors must be considered in the selection and application of tapered roller bearings. This paper presents a discussion of these factors as well as results from Chrysler's transaxle testing. Selection of tapered roller bearings is based on the transmission duty cycle developed using load and speed histograms, gear data, size constraints, and life requirements. A bearing life analysis considering the total transaxle system is conducted using a sophisticated computer program. Various system effects are analyzed including the load/speed cycle, housing and shaft rigidity, lubrication, bearing setting, thermal effects, and bearing internal design.

This paper describes the application of the Design for Manufacture and Assembly (DFMA) method at Chrysler. Attention is focused on the development of the clutch and brake pedal and bracketry system of the PL project in the Small Car Platform. The Chrysler DFMA procedure including competitive evaluation and value engineering was utilized during the initial design phase involving product concept development from the original functional and manufacturing requirements. After the first laboratory tests, a number of key design and manufacturing concerns surfaced and led to a second cycle of DFMA analysis. The procedure permits major design functions and manufacturing and assembly process issues and criteria to be incorporated in the initial design stages.

A selection of commercially available chromium and chromium-free post phosphate rinses along with a deionized water rinse were evaluated over several zinc and zinc-alloy coated sheet steels. The test specimens were pretreated and electrocoated on-line in an automotive assembly plant. The effect of the rinse treatments on the cosmetic corrosion performance of the substrates, after 5 years of exposure in an outdoor scab corrosion test was determined. After this exposure none of the rinse treatments had performed better than deionized water rinse on zinc and zinc-iron coated sheet. The zinc-nickel coating showed improved scribe creepage when treated with the Cr+6/Cr+3 rinse. Data is provided comparing the concentration of the treatments used vs scribe creepage and chipping corrosion paint loss.

A comprehensive selection of automotive sheet steels were exposed in an outdoor scab corrosion test to provide a base-line of cosmetic corrosion performance. Eighteen different coated sheet steels along with CRS as a control were processed using two commercially available zinc phosphate chemistries. The phosphating was done using both immersion and spray phosphate processes in a laboratory and an automotive assembly plant. Scribe creepage results are reported for 5 years outdoor scab exposure. Comparisons of the scribe creepage behavior of CRS, zinc, and zinc alloy coatings and the effect of the phosphate treatment are provided. An estimate of 10 years field performance is made.

Natural gas-fueled vehicles impose unique requirements on exhaust aftertreatment systems. Methane conversion, which is very difficult for conventional automotive catalysts, may be required, depending on future regulatory directions. Three-way converter operating windows for simultaneous conversion of HC, CO, and NOx are considerably more narrow with gas engine exhaust. While several studies have demonstrated acceptable fresh converter performance, aged performance remains a concern. This paper presents the results of a durability study of eight catalytic converters specifically developed for natural gas engines. The converters were aged for 300 hours on a natural gas-fueled 7.0L Chevrolet engine operated at net stoichiometry. Catalyst performance was evaluated using both air/fuel traverse engine tests and FTP vehicle tests. Durability cycle severity and a comparison of results for engine and vehicle tests are discussed.

Typical sand-casting techniques have been shown to be inappropriate in pouring particulate reinforced aluminum metal matrix composite (Al-MMC) castings. New gating/risering configurations were necessary to produce castings of acceptable soundness. Several automotive components, including brake rotors, cylinder liners and camshaft thrust plates, were prepared using special techniques. Initial durability test results of several Al-MMC prototype components are presented.

To evaluate and refine interior architecture of the new Dodge Ram pickup truck three years before production, a road worthy interior package validation buck was built using a fiberglass body shell. Molds for the shell were made using CAD/CAM techniques. Advanced CAD/CAM techniques were used to build the interior buck of a subsequent model from individual panels molded in carbon fiber. This buck also included inner structural panels and interior trim components taken from CAD data. For this and subsequent new vehicle programs, refinement of construction techniques allows the bucks to serve as aids in product design and manufacturing feasibility studies.

Chrysler Corporation has developed an 8.0-liter engine for light truck applications. Numerous features combine to produce the highest power and torque ratings of any gasoline-fueled light truck engine currently available while also providing commensurate durability. These features include: a deep-skirt ten-cylinder 90° “V” block, a Helmholtz resonator intake manifold that enhances both low and mid-range torque, light die cast all-aluminum pistons for low vibration, a unique firing order for smooth operation, a “Y” block configuration for strength and durability, a heavy duty truck-type thermostat to control warm up, and a direct ignition system.

Chrysler Corporation's Jeep and Truck platform implemented a new design and prototype process for the body-in -white of a new pickup truck. A team approach achieved concurrent body design, stamping die design, assembly process development, and assembly tooling development. The first domestic US industry use of a 100% electronic design and release system was instrumental in the process. The new process produced a prototype body-in-white on time at 95 WBVP (weeks before volume production) with the highest level of production-intent components ever achieved within Chrysler at this stage of development.

Most United States vehicle assembly plants produce significantly more automatic transmission equipped vehicles than manual transmission vehicles. Assembling these two vehicles on a common production line can create complexity problems. This paper describes the design and development of a pre-assembled manual transmission clutch and flywheel modular assembly which reduces most of these problems. This assembly is used on the 1993 model year mini-van with a 2.5L four cylinder engine. This modular clutch system utilizes the same starter ring gear carrier (driveplate) used on automatic transmission equipped vehicles. It pilots into the crankshaft similar to the automatic transmission torque converter. It is balanced as an assembly which results in a lower system imbalance. A significant system piece cost saving, in comparison with today's competitive market, was achieved.

Environmental issues have significantly impacted automotive operations worldwide. Countries are continuing to ratchet down their allowable emissions and to remain competitive, all industries must take Life Cycle Management (LCM) and implement it into everyday practice. Economic competitiveness as a part of economic development is central to the nation's social and financial well-being. America must catch-up to the rest of the world in how it views government and industry relationships as well as how to focus costs within the corporate structure. The adversarial relationships between government and industry must give way to stronger partnerships. For this concept to succeed a long term view of problems must be made by a corporation and both short and long term actions taken to resolve these problems. Industry must help create the market for recycled goods and must “walk the talk” by using recycled goods where possible.

The paper outlines testing, development, and operation of the first production four-wheel slip control system for passenger cars in the United States. The Chrysler Corp. calls the system “Sure-Brake,” but it is more generally known as “anti-skid.” The first portion of the paper deals with considerations that led Chrysler into the Sure-Brake system, the philosophy behind the system, and a detailed explanation of its operation. The second portion deals with the development and testing of the system, leading to its release as an option on the 1971 Imperial. The testing program introduced a new dimension to brake engineering. Before the advent of wheel slip control systems, many thousands of brake tests were conducted but were always terminated at the point of skid. These tests were also conducted mainly on black top or concrete roads. For the first time, thousands of stops were made at maximum deceleration on every available surface.

Chrysler Corp. has introduced two new features on their 1970 steering columns: an energy absorbing steering wheel which appears on the Barracuda and Challenger models; and an antitheft steering column which is standard on all car-lines. This paper describes the two engineering programs.

A laboratory test fixture was designed and built to simulate seat belt assembly installations. The anchor positions of the retractor and pillar loop, and the engaged or free-hanging position of the latchplate can be varied to either simulate a vehicle's seat belt system geometry, or to optimize a proposed geometry. The required retraction forces for a simulated geometry are determined by replacing the retractor action with a motorized load transducer that measures the force required to stow the latchplate. The pillar loop, webbing, latchplate, and their relative positions can be varied until the minimum retraction force that successfully stores the latchplate is determined. The geometry of such a condition can then be applied to future designs of seat belt assembly components and their anchor positions.

An automotive cockpit module is a complex assembly, which consists of components and sub-systems. The critical systems in the cockpit module are the instrument panel (IP), the floor console, and door trim assemblies, which consist of many plastic trims. Stiffness is one of the most important parameters for the plastic trims' design, and it should be optimum to meet all the three functional requirements of safety, vibration and durability. This paper presents how the CAE application and various other techniques are used efficiently to predict the stiffness, and the strength of automotive cockpit systems, which will reduce the product development cycle time and cost. The implicit solver is used for the most of the stiffness analysis, and the explicit techniques are used in highly non-linear situations. This paper also shows the correlations of the CAE results and the physical test results, which will give more confidence in product design and reduce the cost of prototype testing.