Also started trying to fix up my mag drill a bit. Got a great deal on a brand new Milwaukee drill motor, the 1 1/4" 4297-1. It's a two speed, 250 and 500rpm, motor with a removable internal sleeve that has a number 3 Morse taper. So I'll be able to use all of my taper shank drills and if also came with an annular cutter arbor that takes a 3/4" Weldon shank and has a coolant inducer ring.
The back of the mag drill had a threaded stud, that apparently was casting into the aluminum base. The stud was bent when I bought it and not useable, but it's supposed to have a long nut or something to thread down into contact with whatever you're drilling and prevent the magnet from lifting.
Had to get a little creative to get it out. Cut the stud off flush. Hung my vise half way off the table, clamped it down and used the magnet on the bottom of the vise. The table didn't move up far enough, but luckily I had two big 3/4" chucks, one with a 3/4" shank arbor. Little sketchy looking but it worked really well to drill the 1/4" pilot hole
After that I drilled it out with an extra long 5/8" taper shank drill directly in the spindle that I didn't get a pic of. Just undersize of the stud, was able to peel out the leftovers of the stud.
Then I used a 2MT to 3MT adapter to use a 13/16" 3MT taper shank drill to drill out the hole larger, being careful not to break through the outside of the handle.
Then back to the chuck in a chuck to get my 7/8-14 tap started straight in the hole
And the final result. Very happy with how if came out, just a few other pieces left to make and I'll have a badass mag drill again