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Gearbox and driveline durability is always been a sensitive subject from both end user and manufacturer’s point of view. Since powertrain is heart of vehicle, naturally it is expected to long last and perform satisfactorily for the entire vehicle life. Sometimes the driveline aggregates especially gearbox might face some issues because of various factors, but this is distinctively noted by the driver since it is one of the important touch point of the vehicle. The gear slippage is a very typical phenomenon observed in automotive gearbox. The issue of gear slippage is very sensitive because it leads to compromising safety of the driver, also it deteriorates gear shift quality and thereby performance of the vehicle. Generally, gear slippage is not observed during end of line testing or during early kilometers of vehicle. It is observed after some thousand kilometers, that to initially gear slippage is not observed consistently and that’s why it is difficult to identify at early stage.

The main objective of the exhaust system is to offer a leakage proof, noise proof, safe route for exhaust gases from engine to tailpipe, where they are released into the environment, while also processing them to meet the emission norms. New stringent emission norms demand ‘near-zero’ leakage exhaust systems, throughout vehicle life bringing the joints into focus as they are highly susceptible to leakage. Needless to say, this necessitates them to endure not only structural but also the environmental loads, throughout their life. Thus, the fatigue life or durability tests become the most critical part of the exhaust system development. Test acceleration and result correlation (for life prediction), to meet the stringent project timelines and stricter environmental norms are the key considerations for developing a new testing methodology. Quality of accelerated tests is ensured by deploying all possible multiple loads, to simulate real-life conditions.

EU directive 2005/64/EC on type approval of motor vehicles with respect to their Reusability, Recyclability and Recoverability ( RRR ) requires vehicle manufacturers to put in place the necessary arrangements and procedures for Parts, Materials and Weight (PMW ) data collection from full chain of supply. This is required to perform the calculations of recyclability rate and recoverability rate in line with ISO 22628. Commonly practiced data collection methodologies included spreadsheet and use of internationally available IT support system for collection of material data. Data complexity and prohibitive cost for using Internationally available IT Support systems like IMDS (International Material Data System) has led to the in-house development of IT enabled Solution customizing Siemens PLM software product (Team centre Enterprise) and SAP (SRM suite).

Success of the vehicle in the market depends on comfort provided while usage, which also include level of noise, vibration and harshness (NVH). In order to achieve good cabin comfort, the NVH levels have to be as low as possible. Powertrain is main source of NVH issues on vehicle and typically mounted on vehicle using rubber isolators. The dynamic characteristics of rubber isolators play vital role in reducing the vibrations transfer from powertrain to vehicle structure while operation and during dynamic conditions. Traditionally, isolators are manufactured using Natural Rubber (NR) to meet functional requirements which include vibration isolation and durability. At times either of above requirements has to be compromised or sacrificed due to the limitation in compounding process and other practical problems involved with manufacturing of rubber parts.

The automotive sector is going through a phase of stiff competition among various Original Equipment Manufacturers for increasing their profitability while ensuring highest levels of customer satisfaction. The biggest challenge for such companies lies in minimizing their overall cost involving investments in Research and Development, manufacturing, after sales service and warranty costs. Higher warranty costs not only affect the net profit but in turn it also affects the brand image of the company to a large extent in the long run. An effort is made here to target such warranty costs due to frequent tail pinion and hub seal leakages on single reduction/hub reduction axles of Heavy Commercial Vehicles in the field. A preliminary study involving the severity analysis of such failures is followed by a step by step investigation of these failures.

Interdependency of automotive transmission aggregates on electrical/ electronics systems is increasing day by day, offering more comfort and features. For a system integrator, it becomes very much important while selecting/designing any such component to take into consideration the relationship between such interdependent components from performance as well as endurance point of view. DMF failures due to inadequate starting system, is a major stumbling block in development of DMF for a particular vehicle application. The interface of DMF and starting system of a vehicle makes it essential to consider the effect of one on another. The study shows that the majority of DMF failures happen because of resonance phenomenon in the DMF during engine starting. The improper selection of starter motor makes the DMF more vulnerable for such failures.

Power-supply forms a key hardware block for every automotive ECU. Apart from delivering robust and reliable logic supply voltages it is also burdened with many auxiliary tasks like transient protection, good EMI/EMC performance, Power-hold function, Analog Sensor supply voltage etc. It also needs to meet all automotive norms including short to battery/ground etc. This paper discusses low cost implementation techniques which maximize the value delivered to the vehicle application at minimal cost. Innovative techniques are described for combining sensor and logic supplies wherever applicable. Hurdles faced during such circuit optimization are clearly explained along with the solutions adopted to overcome hurdles yet meeting automotive test norms. A novel low cost concept which combines transient protection as well as power-hold function (without using the conventional relay based technique) further adds value to the end application.

Success of the vehicle in the market depends on comfort provided while usage, which also includes noise, vibration and harshness (NVH). In order to achieve comfort level, the NVH levels have to be as low as possible. Powertrain is the main source of NVH, in which internal combustion engine consists of crank shaft and balancer shaft. Crank shaft gear is connected and driven by crank shaft and balanced by integral eccentric mass coupled with gear. Balancer shaft is used for additional balancing of rotating masses. Pair of crank shaft and balancer shaft gears generates noise and vibration when unbalance in the system and backlash in the gears increase while usage. The practice of interposing a vibration isolator on the surface of gear has been so far resorted for preventing transmission of vibration, therefore reduction in noise. In the work presented, balancer gear was made with sandwich design to reduce noise. Sandwich design comprises of Inner hub and outer ring with lug projections.

The commercial vehicle market in India is shifting to higher payload capacity vehicles due to a lower transportation cost per unit goods. To cater this requirement, the vehicle manufacturers are designing the heavy multi-axle commercial vehicles and with higher per axle loading capacity. One of such a vehicle design involves five-axle vehicle with non-steerable, twin tire, lift axle. Though using a twin tires have increased loading capacity of lift axle compared to a single tire self-steerable lift axle, it can cause tire scrub while vehicle is turning and leads to a significant tire wear. The tire wear possibility due to use of non-steerable lift axle is estimated through simulation using full vehicle model in ADAMS. The operating zone of the vehicle, where maximum tire wear can occur, is identified through simulation. Different alternatives to reduce tire wear for this scenario are also discussed.

In recent years, car manufacturers have been working intensively on new ways to improve the quality of interior trims. Elimination of squeak and rattle has become one of the main concerns for car manufacturers lately, given the significance of these incidences in customers' perception of overall quality. Traditionally, rattle problems are found and fixed with physical tests at the late design stage, mainly due to lack of up-front CAE simulation prediction methodology and tools availability. This article presents a finite element based methodology for the improvement of rattle performance of a vehicle tailgate. In this study, appropriate finite element (FE) modeling technique was introduced to accurately predict occurrence of tailgate rattle. Simulation process using commercial software “Nastran” employing modal and forced frequency response analyses was illustrated. Design modifications were incorporated for performance improvement of rattling on present and future SUVs.

The present work focuses on optimization of gear shift pattern of an AMT vehicle to improve its NVH performance without causing any adverse effect on any other vehicle performance attribute. The vehicle which was identified with the structural body resonance at low frequency had discomforting boom noise in a particular engine rpm zone and at corresponding vehicle speed. With the initial shift pattern (will be referred as V1 gear shift schedule), the gear shifts were calibrated such that when vehicle is driven in the city with 20 to 60 kmph speed, the vehicle operated mostly in the best fuel economy zone but it used to pass through structural resonance frequency. This resulted in the presence of continuous boom leading to an unpleasant driving experience. In order to avoid the presence of boom noise during city driving, the gear shift points were optimized (will be referred as V2 gear shift schedule) such that the vehicle did not operate in affected engine speed range.

Gearshift quality is a perceived quality parameter. Hence, is getting much importance because of the increased awareness about comfortable and refined driving experience, especially in the case of passenger cars. When the topic of gearshift feeling is broached in manual transmission vehicles, synchronizer pack (shifter sleeve, engaging gear, strut, synchronizer and gear synchro ring assembly) have been the focus point for optimization. Synchronizer type (single, double or triple cone), lining material, datch chamfer angle of shifter sleeve/synchro ring of gear/synchronizer, all of these have been extensively studied in the past to improve the gearshift quality. With stringent timelines for vehicle development, OEMs prefer to use off-the-shelf powertrain systems developed by powertrain manufacturers. Due to this, avenues to refine gearshift feel gets reduced to a large extent and hence refinement becomes difficult.

Powertrain mounts locations and stiffness in vehicle plays very important role in improving vehicle noise and vibration, which is caused by engine firing forces and road disturbances. Once locations are finalized, based on initial calculation and packaging then it is very much critical to play with mount stiffness to achieve required NVH level in vehicle. This paper describes the effect of mount stiffness on the bolted joint integrity. Stiffness fine tuning is done to improve vehicle level NVH and various iteration are done with change in stiffness values of A, B and C mounts. When stiffness specifications are finalized, it is recommended to acquire road load data on the finalized stiffness mount and check for bolted joint integrity since load signature is varying significantly on mount w.r.t stiffness change. If we change mount stiffness value from 128N/mm to 98N/mm, then loads on particular mount is getting increased from 4.5KN to 6.5KN in one of the track testing.