Ron,
I thought, from your initial post, that you were trying to reassemble the GB with the new compound gear. Are you saying that although it went in easily 3", now it does not want to come back out? If so, one possibility would be to buy a split clamp to fit the spindle. Or better, buy two. Also find or buy a piece of steel about 2" dia. and 3" long. Drill a spindle slip fit hole in the steel and deburr each end so that you don't scar the spindle. Slide the holey steel round onto the spindle and mount the two clamps near the end, tight against each other. Use the round as a slide hammer.
Robert D.