Notes: 208-7862/HESO19506 AXLE SHAFT WITH GEAR z=13 m=3 is original CATERPILLAR product. 208-7862/HESO19506 AXLE SHAFT WITH GEAR z=13 m=31 is commonly used in transmissions/axles/engines . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849