12JS160T-1701123 pinion washer is a precision shim part matched for Fuller 12JS160T and 12JS200T series heavy-duty gearboxes of Sinotruk Howo trucks. It is installed on the main shaft of the gearbox, acting as a clearance adjustment and wear buffer gasket between the main shaft gear and related mating components. Made of high-strength alloy steel and treated by quenching and tempering heat treatment, the washer features high surface hardness, excellent flatness and wear resistance. It can bear large axial impact and friction load during gearbox power transmission, control the axial clearance of the main shaft gear accurately, reduce gear shaking and abnormal noise during operation, and prevent direct metal friction between contact parts. Each washer undergoes strict flatness, thickness tolerance and hardness inspection before delivery to ensure assembly accuracy and stable gear meshing. When the original washer is worn, deformed or thinned, this spare part can be used for direct replacement and gearbox overhaul. We maintain sufficient inventory and stable bulk supply for repair workshops, fleet operators, auto spare parts dealers and global cross-border export customers.