We secured a pair of Yukon's Dana 60 Super Joints to further strengthen our front drive system. These U-joints were machined from a solid chunk of through-hardened 4340 steel and then treated with a titanium nitrate coating (the gold color), giving it super-high-wear characteristics. This allows the cross to ride directly in the induction-hardened 4140-chrome-moly caps with very tight clearances and without a separate bushing or needle bearings. Lacking separate cap bushings or needle bearings, the trunnion is larger in diameter as well, adding to overall strength. The trunnion on the Super Joint is some five percent larger than a traditional Dana 60 U-joint (0.935 versus 0.892 inch). A special 200,000psi compressive strength copper-based grease is included with the pair, along with a compact and very handy grease gun. Yukon says that this is the only grease you should use with the Super Joint.