Help!!!

[Frank S]

OK here is a start for you to think about
this tool would only do the inner race area in the current configuration but you could have a nice little belt sander when finished LOL
to start off you would want to protect the seal surface area from any possible weld splatter and obviously the outer bering surface and thread areas.
the whole assembly would slide over the spindle then use the outer nut just tight enough to hold it in place you would rotate everything around the spindle adjusting the depth of cut as needed until the spindle was repaired and ground to the correct diameter you would be able to use a micrometer to check the diameter without removing the tool hopefully.

I didn't add in any dimensional specs since you will be constructing this yourself

I believe you should be able to see most of the parts involved. It is a bit more of a complicated build than a simple jig but if done this way y9ou will have a guarantee that your spindle is fully concentric you will just have to be careful not to dilly dally around while grinding otherwise flat spots will develop

the size of the belt I have drawn in could be a standard 3or4x24" belt ripped to 1 " wide that way you can buy them almost anywhere and you would get 3or4 for 1
years ago I made up something similar to repair the end of a hydraulic cylinder rod so I know the idea has been tested to work.
with just a little more complicating of the build the seal area as well as the outer spindle area can be repaired in a similar fashion making a single point attachment to re-thread the spindle really adds to the complexity of a build but I once started top design a portable rotary lathe to do something like this for Large hydraulic cylinders