[rotorwrench]

There are a number of wear areas that can contribute to 2nd gear push out. When helical gears became common in the semi-synchronized 3-speed transmissions, the design had to be set up to counter the thrust loads that happen with them. Under load, they thrust one direction and under engine braking, they thrust the opposite direction. When the transmission is new, all the thrusting loads are pretty well countered but as things wear, they aren't counteracted as well. Gears wear, rotating bearings and bushings wear, synchronizer blocker rings can wear, shafts wear, and thrust bearings wear. All of this and wear in the shift tower detents can have an affect. With wear, the input shaft can wiggle around and main shaft will can move around with it. The cluster gear can move a good bit fore and aft as well as a bit of wiggle depending on where the worst of the wear may be. The second gear can woble a bit on the bushing it rides on and the syncho is going to move around a bit too if the shafts & are moving around too much. All this stuff can have an affect.