Dick,
Good luck on your investigation.
You might try reading this for other ideas:
http://www.santaanitaas.org/wp-conte...ut-of-Gear.pdf
Tom is very good at explaining technical issues.
Also, we were talking at our club's seminar about the shifter plungers and spring that go into the detents might have an incorrect shape and not fully engage the detents. You might check those against the ones you pulled out when you get it apart.
Jerry