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 was identified to improve the pin profile along its 30 mm length. Based on measurements, it was found that, due to variations on the order of five microns, the pin profile (nominally linear) may vary between concave or convex shape. Process improvements were focused on the form grinding profile. The amplitude of the grinding profile was established between zero and five microns tending to convex shape. An action plan was implemented to achieve process capability for the proposed improved condition, which required greater restriction on the extent of the grinding profile for three and half microns. The improvements were based on changes to following crankshaft manufacturing processes: the steadiness of the journals in semi-finish grinding, the dressing frequency and feed rate of the finish grinding wheel, and the paper grit for superfinishing. This study and improvements implemented brought benefits to the crankshaft manufacturer and customers, reducing product inspections and increasing product robustness.