Hi found this in a box I check E/bay & Google with no luck.
??? does that outer sleeve have pipe threads ?? or the same as a spark plug thread ??
what size is the sleeve diameter ?
how long is the bolt ???
just looking for some clues.
I think it is some kind of puller. Look at http://kar.ca/ (http://kar.ca/) KAR Industrial.
GM a/c compressor pulley tool ?
If that thing is threaded all the way thru; and the end is threaded to go into the spark plug hole...my guess would be a stop for checking for top dead center when setting up a new timing on an engine.
I believe that couchspring & lostmind are on the right path.
google; A/C clutch hub remover tool.
I'm leaning towards the TDC idea. Haven't seen one in years but that's how I remember them.
I have used TDC finders, but don't think I would use one that is threaded and might be set too deep and stop piston travel before TDC.