Triumph Repair: Tr 4a Transmission, top cover, axle grease, two balls

Question
Need ideas .  I just replaced the  three leaking "O" rings in the gear selector chamber.  Now, how do I  reinstall the two balls ( the book term) on either side of 3rd gear selector shaft ;  there is only one expansion plug hole to push in both balls. Will the recommended grease do the trick if I position one ball into the 3rd shaft and then rotate this shaft 180 degrees for the first metal ball...I figure that if this works then the second ball must not be  a problem.
Can  you offer any other ideas? Thank you for your thoughts.

Answer
Hi Roberto,
If you only have one access hole you can first install the selector shaft that is furthermost from the hole, then install a ball and move the shaft until the notch (detent) in the shaft is lined up with the ball. Then insert the lock-out plunger into the 3rd/4th shaft. (a little axle grease will hold the plunger in place) Then install the 3/4 shaft so the plunger is lined up with the ball already installed. Now you can install the second ball. Push the ball into place so as to force the plunger against the first ball and if you have the notch in the other shaft lined up correctly the ball will recess enough to install the last shaft.
Howard