Rod & Pin Optimization on 6.4L Heavy Duty Engine for bushing wear and noise reduction

This research paper on a problem that has persisted over the years in heavy-duty engines is commonly known as "pin tick." It refers to a condition whereby there is very significant wear of the rod bushing. The problem was observed in various heavy-duty engines, whereby wear exceeded 30 μm with noticeable play between the rod bushing and pin. With previous attempts to solve the problem—like implementing roundness specifications for the pin bore—the problem still prevails. Testing procedures for noise, vibration, and hardness were carried out to understand the challenge completely and to arrive at a solution. All these tests pointed to a lubrication-related root cause of the problem. Our research in this field has been largely focused on evaluating the performance of a new chevron-grooved bushing design. The validation program included a full-scale CAE simulation, proof-of-concept tests, and other design and process validation tests. This paper discusses in detail the methodology and findings from this investigation in finding a sustainable solution to arrest rod bushing wear in heavy-duty engines.