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In the era of fierce competition, launching a defect free product on time would be the key to success. In a modern automobile, the transmission system is designed with utmost care in order to transfer the maximum power from engine to driveline smoothly and efficiently. Optimized design of all the transmission components is necessary in order to meet the power requirement with the least possible weight. This optimization may require gear designs with different internal diameters. The assembly of these gears may not be possible on a solid transmission shaft. To facilitate assembling while retaining optimum design of transmission parts, a separate bush is designed to overcome this limitation. Some bushes may require a flange to restrict any free play of the mounted gear in its axial direction. During complete system level testing of one newly developed manual transmission, bush failure was observed.

The demand of gear shift quality in vehicles has increased considerably in the past few years. The gear shift is the key interface between driver and vehicle transmission. The essential criterions for the operating quality of the gear shift is the operating force and feel on the gear shift knob at each stage of gear shift, starting from start of gear shift to the end of gear shift. This paper deals with techniques to reduce secondary force due to synchronizer sleeve hitting on dog ring at the end of gear shift which is also known as Double Bump. The double bump ratio should be less than 0.4 to achieve the best in class shift feel for passenger car segment. Normal driver will not feel if double bump ratio is less than 0.6. Inertia mass mounted on shift system of manual transmission helps to generate momentum at the end of gear shift to nullify the double bump force.