How to Loosen a Thread Pin from Bottom of Motor Shaft

You are welcome, I could have written a 1000 word explanation with diagrams and pictures but YOUTUBE already had something that would show you which tools to use and how to apply the tools to your application.

Good luck on your project!

P.S. My work blocks YOUTUBE so I just kind of guessed at the search term!

If there is no snap ring, then lyn has given you your answer.

I doubt there was a snap ring on the shaft, because the OP said they removed a nut. I have never seen a snap ring on a shaft that was attached by a nut. And a key!

My 72" finish mower on my farm has 8 pulleys on the main drive belt. All of them have a snap ring underneath the retaining nut.

I stand corrected!

Is there a clear reason for that, or is just belt and suspenders engineering?

My WAG is that the snap ring is a safety backup. The first time I changed out a pulley I didn't know about them and utter destruction ensued.

LOL! I only laugh, because I have been there, done that, got the T-shirt, and never went back for another.

No matter what he uses to remove the pulley, if the key is a flat bottom on or a round bottom one---

Be extremely careful, you could damage the pulley bore or the shaft. Not nice things to be confronted with. Be slow, gentle and repeated small taps with a brass/bronze hammer are the best way most often.

Good Luck, Old Salt

Midnight Cowboy was the only one to suggest judicious application of heat

Warming the pulley and not the shaft? It works for me.

I think heating either will put some (maybe not intense) heat on the other. Either way, the expansion should cause the pulleybore and shaft OD to open up, accept lubricant/penetrating oil, slightly reduce the iron oxide (if present).

Good stuff, all.

A truer statement has never been made.

Gradually lower the temperature of the shaft by gradually applying dry ice to it. Slow enough that the shaft metal cools but not fast/cold enough to crack the shaft metal. When loose enough pull the pulley off the shaft. If an induction heater can heat a bearing dry ice can cool a shaft!

or--

Make a "crude but safer" pulley/gear puller". Example for a 3/4" shaft with a soft sided pulley on it cut two pieces of 1/4=3/8" thick x 2" wide steel about 2-3" longer than the diameter of the pulley. Mark one at the length and width center and also at a point both equidistant from the center but wider apart than the pulley diameter plus 1". Drill a 7/8" whole in the center of one and cut/grind away from this hole a slot the same dia. as the hole to one side of this piece. Next drill holes in each end at the furthest marks and drill a 33/64" hole in each. Slide notched piece over shaft between pulley and motor. Place blank centered piece at end of shaft at center of pulley bore. Put 1/2" cap screws, preferably fine thread, through these holes and put flat washers and nuts on these bolts. Tighten up bolts evenly and the pulley will come off. Tap center of outer piece with hammer just like would be done with a gear puller. Since the outer diameter of the pulley is not being pulled there will be no distortion. Added benefit is that it will not peen over the shaft end from hitting it with a hammer if brass hammer is not available. Works like a 2 jaw puller but doesn't distort the pulley.

Before doing this, if the pulley is so stuck on that you can not pull it off by hand use liberal applications of "Blaster", Liquid Wrench or similar products.

This works good especially when the idiot down the street who borrowed your lawn mower but hasn't returned it yet tells you that his "brother-in-law" borrowed his gear puller just that morning.

Good Luck, Old Salt

If you have room between the pulley and motor I would suggest you use a bearing puller plate to avoid damaging the pulley.

Most automotive parts stores have tool rental or loan services available where you can get the size needed.

Anatomy of a taper lock pulley, famous for rusting on permanently:

Otherwise known as a mechanic's nightmare waiting for him to go to sleep.