So, I was driving my '92 Geo 5 Speed to work this week and it started popping out of 5th gear.  I can try to hold it in, but it keeps wanting to kick out.  I've seen general information on the Internet about this, but not much about Trackers specfically.

Possible causes I've heard of so far:
1) Loose shifter linkage
2) Loose motor mounts or tranny mounts
3) Main tranny bearings have too much play
4) Gears physically damaged
5) Bad synchro

Any ideas before I try to look at it?  Maybe I should just skip to asking who has a 5 Speed automatic tranny they want to sell? 

Thanks!

~Brad