I have an 1855 that we bought new in 1973.  It has untold number of hours on it, two overhauls, but that's all its ever needed.  Recently, it has started to very occasionally get stuck in two gears.  I pulled the gear shift and looked down and the slide rails look OK.  The gear shift has some wear where the top rail contacts it, but the ball looks good.  This wear doesn't look too bad as I pulled the shifter on my 1755 (with only 3200 hours on it) and it looks very similar.  Everything seems to be fine.

Any ideas on what is going on here?  I made a mistake this winter and pulled the gear shift with it in gear while putting a new hydraulic line on it and had some trouble getting it back right.  But, it worked fine for a while after that, so I kinda ruled that out.

Any suggestions or history on a similar problem would be appreciated.

Thanks