GM-50712 is a 6-segment expandable collet tool used to remove the carrier bearing 57 mm cup out of the transmission case. The tapered lip on each segment wedges between the flat end of the cup and the bottom of the cup bore. As the hex collar of the tool is turned with a wrench, the segments expand and capture the cup.
The forcing screw from the previously essential GM-45124 Puller Bridge and Leg Assembly is threaded into DT‑50712, and the legs are spaced slightly wider than the cup OD and tightened. Turning the forcing screw gradually pulls the cup up through the bridge legs to remove it without scoring or damaging the aluminum case bore.