Notes: 208-9015/GEUG59697 BEVEL GEAR PINION KIT 13/31 is original CATERPILLAR product. 208-9015/GEUG59697 BEVEL GEAR PINION KIT 13/311 is commonly used in transmissions/axles/engines . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849