The John Deere AM136357 is an authentic OEM idler pulley designed for various John Deere mower decks. This crucial component ensures proper belt tension and smooth operation of the mower deck, contributing to efficient cutting performance. It is a direct replacement part for a wide range of John Deere X-Series lawn tractors, including models like X300, X304, X310, X320, X324, X340, X360, X500, X520, X530, X534, X540, and Z-Series zero-turn mowers such as Z425, Z445, Z465, Z525E, Z535M, Z535R, Z540M, Z540R, Z645, Z655, Z665, Z710A, Z720A, Z725I, Z730M, Z735E, Z735M, Z740R, Z760R, Z810A, Z820A, Z830A, Z840A, Z850A, Z860A, Z910A, Z915B, Z915E, Z920A, Z920M, Z920R, Z925A, Z925M, Z930A, Z930M, Z930R, Z950A, Z950M, Z950R, Z960A, Z960M, Z960R, Z970A, Z970R, Z997R. Replacing worn pulleys with genuine John Deere parts helps maintain the longevity and optimal function of your mowing equipment.