Tool to (hopefully) ease working with sliding assemblies that contain spring-loaded detent balls (e.g. manual transmission shift forks). Rather than sliding the assembly straight off the shaft and trying to keep the detent ball and spring from flying off into the unknown, the assembly can be slid off the shaft and onto the this tool, and will remain held in place by the detent ball. Be sure to hold the tool firmly against the end of the shaft as you do this!

The kind of thing that could trivially be turned up on a lathe, but I don't have a lathe, and do have a 3D printer, so here we are :)

Default dimensions are suitable for the shift forks of a Peugeot BE1 transmission.