Re: I could use some help
Shift shaft, item 36 is held in the lower unit by the E ring, item 37. It is not uncommon for them to have been previously left out or popped out if someone pulled upwards too hard on the shift shaft.
When properly installed the shaft lower splines fit into cam, item 17. Here is a picture of it so you can see what I mean:
http://imageshack.com/a/img828/3793/glm11185.jpg
Depending on what gear it was in before the shaft was pulled out, you may be able to get the shaft splines re-inserted into the cam but it is tricky. Probably the easiest at this point and to recover the E ring, is to remove the bearing carrier assy which will give you access to the cam. You will need the service manual for this, P/N 90-830234 and if you do not have it, see my message to you in Notifications at the top of this page.
Do you have the s/n of your engine?
Gerry