Spicer parts from Dana are trusted around the world for their high performance and outstanding durability, and now Spicer brings you their toughest u-joint yet: the Spicer Extreme u-joint. These u-joints can take any off-roading punishment you can dish out. They are virtually indestructible! Featuring a SAE-4340 nickel chromoly steel cross with an enlarged trunnion diameter for added strength, Spicer Extreme u-joints allow you to crawl over every boulder and come back for more. For off-road use only.