en سازه Body structure پژوهشي Research <span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times="">In this paper, the strength of the gear shifting blocker for Peugeot gearbox is investigated. A hardened steel sheet is used inside the plastic part of shifting blocker to strengthen it. According to the feedback from the customer that this part fails in some conditions, some suggestions for its improvement are presented. In this research, two proposed correction designs are presented to increase the strength of the gear shifting locker by changing on the considered steel sheet. Abaqus software has been used to model the gear shifting blocker and analyze the stress of parts by finite element method. In order to validate the analytical results and choose the proper proposed design to strengthen the blocker part, some experimental tests are performed on the tension-compression test device. By comparing the results of the numerical analysis, it can be observed that the first and second modification designs have improved the stresses of blocker plastic part by 18% and 45%, respectively.</span></span></span> Strength improvement, Gear shifting blocker, Fork, Finite element analysis, Abaqus software 4369 4377 http://ase.iust.ac.ir/browse.php?a_code=A-10-650-2&slc_lang=en&sid=1 Milad Arianfard milad.arianfard@gmail.com 180031947532846004729 180031947532846004729 No Department of Mechanical Engineering, National University of Skills (NUS), Tehran, Iran Abbas Soltani soltani@bzte.ac.ir 180031947532846004730 180031947532846004730 Yes Department of Industrial, Mechanical and Aerospace Engineering, Buein Zahra Technical University, Qazvin, Iran.