Speedometer woes, need transmission advice.

[Smeins, Larry]

Not too long ago I was asking for speedometer advice for my 87 5kcst 5 spd.
I replaced everything electronic before discovering my problem was the
plastic drive gear in the transmission, at least a new one fixed it
temporarily.  The drive gear that I removed from my transmission had grooves
worn in the section below the gear and was roughly stepped into two
diameters in that section.  The new gear was smooth and of one diameter in
the lower section.  My speedometer worked for about 3,000 miles with the new
gear before it became intermittent and soon stopped completely.  When I
pulled the new gear it looked just like the old gear, heavily worn in the
lower section.   It looks like I've got a problem deep in the transmission.
I have a few questions for someone that is familiar with the innards of the
5kt manual transmission.  1. Is the lower end of the speedometer gear
supported in a bearing or is it just carried in a bore in the case?  2. If a
bearing, what type is it?  3. If a bearing, what chance is there to replace
it without disassembling the transmission? (dreaming?)

I am thinking of machining a sleeve bearing with an inner diameter slightly
smaller than the original gear shaft and OD a press fit into the existing
rough bore.  Then cut down the gear shaft to fit the sleeve and press the
sleeve into the transmission to make a new bearing surface.  This would
involve machining an installation tool, too.  I hate to try this without
knowing what is in there.   Anybody in the Boulder, CO area know where I
could look at a disassembled transmission?   Maybe a boneyard transmission
would be a better choice or just go without a speedometer.

Help!  Any and all advice appreciated, even if its something I don't want to
hear.

Larry