My memory is a bit fuzzy. I recall checking to make sure things we're freely rotating throughout to check if the parts were meshing properly. These are the steps where I used the shop press:
Using a plastic hammer, I got the components started on the back half of the counter shaft. I did this so I could place the transmission on the press without having these parts fall off. It was a pain getting the transmission balanced on the plates of the press; but once there was enough pressure, my hands were free to slightly rotate the input shaft. The piston of the press was on the front end of the counter shaft. The back half sat on metal plates. By doing this, I could make sure things were sliding into place without chewing teeth up.
Before it was all snug, I remove the transmission from the press so I could use a set of feeler gauges to make sure the back side of the counter shaft was assembled with the right clearance. Once I had everything back on the press, I snugged everything down. I then set the transmission on the bench and used a puller to removed the feeler gauges. I tightened the puller in degree increments until I could remove the feeler gauges. Then I rechecked the clearances to make sure I was within the recommended tolerances.
