Although I have the Jeep-recommended flange-holding tool, this is an alternative that works: I protect the yoke flange with a rag and hold the yoke while tightening with a large torque wrench. The initial tightening is done with an air gun, set below the final torque recommendation. Follow the Advance Adapters instructions for installing the new yoke seals that are provided. I back this up with a thin film of Super 300 sealant on the yoke splines. Yoke nut threads benefit from Loctite 271 to ensure that they will stay in place.