Military Truck MRAP MAXXPRO Axle Spider Gear Differential Gear Rebuild Kit. This kit contains the spider gears the spider and side gears for a Meritor 120 125 axle. These are used in Military trucks such as the MRAP MAXXPRO also used in civilian trucks check your parts books. Navistar PN# 2508077C91 Meritor PN# KIT1846 NSN 3020-01-566-5353 Save $$$ here as this kit normally lists for over $800 so get a deal here 12661 R2C3