This is the Jeep-recommended tool for holding the flange. The final torquing is with a large torque wrench. Make certain that the yoke flanges have been properly sealed and torqued to specification. Once done properly, these yokes will not need further attention. Note that both output yokes are now CV-type. The new Advance Adapters rear yoke flange will accept the popular 1310 Spicer CV joint.