Advance Adapters provides a special lubricant that works best in the Atlas line of transfer cases. It is very important to fill the planetary reduction housing prior to installation. Once installed the reduction unit cannot be filled. This housing holds a six-gear planetary assembly that has a low range of 2.72:1 and a 1:1 in high range. This planetary assembly has been rated to withstand 5,555 lb-ft of torque and up to 11,000 pounds gross vehicle weight.