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This case study describes improvements to the pin grinding and superfinishing processes for a 900-mm long, 60-kg forged crankshaft used in a six-cylinder diesel engine. Machining vibrations caused by the eccentricity of the mass of the pins in relation to the journals increase the difficulty of achieving a stable and capable process. Through analysis of the crankshaft and connecting rod assembly, an opportunity is identified to improve the pin profile along its 30-mm length. Based on measurements, it is found that, owing to variations of the order of 5 μm, the pin profile (nominally flat) may vary between a concave and a convex shape. Process improvements are focused on the grinding profile. The amplitude of the grinding profile is established between 0 and 5 μm, tending toward a convex shape. The practical implementation of the proposed improvements involves the imposition of a greater restriction on the extent of the grinding profile to 3.5 μm.

Automotive industries have been seeking quality excellence as a key factor in competitiveness. Product characteristics and functions should meet the expectations of customers in terms of warranty and reliability. The objective of this paper is to present a method to improve the synchronization of customer’s product requirements with their suppliers in terms of key performance indicators. The improvement allows suppliers to take corrective and preventive actions through knowledge of component applications in engines and vehicles. Engine assembly lines maintain records and meet daily meet to explore trends of productivity, and supplier quality performance is measured based on engine failure instead of parts supplied. This methodology integrates Lean Manufacturing and Supplier Quality Engineering and respective targets, combining efforts towards Quality Assurance.