Finally, a true ROCKCRAWLER transfer case gear set for for the Nissan D21 Hardbody 4x4! Our gear set is manufactured in the USA from SAE 8620 alloy bar stock material. For long wear life and operation at high speeds nothing else is acceptable. This gearset provides a final low range reduction of 3.92:1, which is a whopping 93.86% lower than stock! It completely transforms this vehicle's off road crawl capability and enables it to perform much better in heavy off-road use situations. This gearset will fit all Nissan TX-10 transfer cases available in all Nissans worldwide. The complete gearset comes with precision machined counter-gear, input gear, and output gear, billet machine retainer ring and bearing as well as two(2) quarts of Valvoline 80W90 gear oil and Permatex RTV silicone gasket maker