With mine , I dripped naptha ( white spirits) down the top of the indicator and also on the under side of the shaft. Then tried to get it to rotate. Once I had it rotating, then I could get the plunger moving up and down. In my case , when it was free and the naptha dripped out the bottom of the spindle, I then dripped baby oil onto it. Just high grade mineral oil. Now it is fine and no issues. I see in the link Clive gave, that the use of thinned ATF. Not sure if it matter if it is mineral or synthetic, but may be worth a try. I would keep actone away from the indicator, and would stay away from WD40 and similar products as well, as suggested above and in the link from Clive. Thanks again and now I know how to take it apart if needed. The accuracy of these indicators, relies on the very close fit of the shaft to the bushes. A great and very useful piece of kit. Mine was new in about 1986 or so, certainly no newer than 1987.
I dont run mine any faster that 200 rpm, as the dial is too quick to see what is happening, depending on the bore size being indicated of course. I just wish that there was a ruby stylus available for them. Does anyone know of such a stylus? Thanks ,
Neil