Yukon Super Joints offer an upgrade in strength over factory u-joints and excel in extreme off-road applications. Designed for Dana 60, Dana 44, Dana 30, and GM 8.5 differentials, Yukon Super Joints feature a 4340 chromoly cross and caps made from 4140 steel to isolate the wear to the caps not the cross because its a lot more convenient and less expensive to replace the caps. The end of each trunnion is home to a reservoir for the grease. Youll notice the trunnion is larger in circumference and therefor considerably stronger than to conventional u-joints. This is because the Super Joint design eliminates the needle bearings. The trade-off is these joints require frequent maintenance as sealed needle bearings contain their grease for a lifetime and Super Joints require regreasing, so we do not recommend installing them in daily driven vehicles.