Hello - I just removed my 1970 CT175's gear shifter cross shaft (getting ready for a crank rebuild) and it looks like it's twisted where it necks down to the splined end.  Is that what is happening and will it eventually shear off?   The rest of the shaft is clean, rust free and no other wear or damage to it or other bits I've taken off so far.  Thanks for any comment.
 

Hi Landyr67g, looking at your posted picture of the gear shift shaft, from a mechanical engineering perspective I don't believe you need to worry about that shaft shearing. The actual shaft if you look at the recessed sections show no sign of torsional stressing or 'waisting'.  It's a slight optical illusion but what is actually twisted are the high spots on the splines. I'd bet a pound to a penny (dollar to a cent..lol) the twisted splines were caused by a loosely fitted gear change lever and the tightening bolt hadn't been done up correctly.  Simply dress those splines up very lightly with a fine needle file and attach the gear lever properly with a tightened bolt and you'll be good to go.....oh once you've done all the hours and hours of other engine work on a crank rebuild. Good luck with it all and hope this helps, Andy