MTFCA Forum

I can not get the micrometer on the tail shaft to get an accurate measurement. I am told that the end of the shaft is normally square but mine has a rounded off face. Not much but maybe an 1/8 rounded end. I can get the micrometer into the shaft be not far beyond the rounded off end.

I'm assuming you are referring to the part of the tail shaft that the uni sides on, then all 4 edges of the flats are rounded off the full length of the square shaft. Why do you need to measure it with a mic?
If you are talking about the shaft off the drive plate to get a measurement for the ball cap babbitt, that should be the same diameter right to the end.

There are a variety of caliper extension kits on the market for under $50. Mine clamp onto caliper jaws and can get into places that the caliper alone can't.

The edge of the tail shaft was factory rounded to eliminate the sharp edge.

I bought a caliper with extra long jaws. The adapters mentioned above should be fine too.

That shaft can be pretty worn. dont expect it to be the same diameter along the whole surface where the 4th main has run. One way to get the measurement is to use a caliper on the 4th main, slip it onto the shaft with a feeler gauge to determine the difference.