*Article* **Influence of Clearance on the Rocker Arm Pin on the Steerability and Stability of the Vehicle Motion**

**Krzysztof Parczewski \* and Henryk Wn ˛ek**

Department of Internal Combustion Engines and Vehicles, Faculty of Mechanical Engineering and Computer Science, University of Bielsko-Biala, Willowa Str. 2, 43-309 Bielsko-Biala, Poland; hwnek@ath.bielsko.pl **\*** Correspondence: kparczewski@ath.bielsko.pl

**Abstract:** The article presents an analysis of the impact of a malfunction resulting from excessive clearance on the rocker arm pin of the front suspension on the vehicle's steerability. The first part of the article presents an analysis of the influence of the clearance on the rocker arm pin on the geometry of the suspension and steering system. The occurrence of forces acting on the rocker arm pin in various phases of the vehicle motion was analyzed. To assess the vehicle's steering, the vehicle's response time to sudden steering wheel movement was used. The vehicle's response time to sudden movement of the steering wheel was used to assess the vehicle's steerability. The second part presents the results of bench tests and traction tests of a vehicle equipped with a specially made measuring rocker arm with the possibility of simulating a clearance. The tests were carried out on a class B passenger car in selected road tests. The results of measurements obtained for the roadworthy vehicle and the vehicle with the rocker arm with clearance were compared. The influence of the clearance on the rocker arm pin on the change of vehicle steerability in steady and dynamically changing conditions was analyzed. The test results show the effect of clearance on vehicle steering and on the vehicle steerability. The study tried to determine to what extent the clearance on the rocker arm affects the vehicle's steerability and thus the safety in road traffic.

**Keywords:** clearance on the rocker arm pin; vehicle steerability; steerability tests; road safety
