Taper pulley removal

[CajunRider]

I need to remove the pulley of my flail mower so I can replace the bearings. It is one of those taper fit pulley. Unfortunately I stripped the threads of 3 of the six holes where the jack studs push the "swellable" taper part out. So now I'm stuck. What should I do next? Drill and tap new thread? Cut the pulley out and replace the whole thing?

 

[ktm250rider]

Drill and tap
Bigger is better

 

[CajunRider]

I kinda figure that but I was hoping for some thing easy, or perhaps more satisfying, like "Heat it with your torch and beat the crap out of it."

 

[KYErik]

Can you get a puller on it? If so, is it heavy enough to put a lot of force on without damaging it? If the answer to both of these questions is "yes", then several auto parts stores have a tool loan program that makes tool rental "free" (you pay for the tool, use it and then take it back for a full refund). I know they have loaner pullers.

 

[RNeumann]

Brute pulling force is not always the answer. Apply the puller or 3 remaining pusher threaded holes so it is tight but prior to stripping threads! Start to tap/hammer the pulley and the shaft the pulley is attached to. I've found more than once this type of shock load will cause the press fit to pop. The second approach is to heat the pulley. This will cause it to expand and with some pulling force should come off. No need to ruin the pulley.....yet.

 

[CajunRider]

The machinist at my plant is saying the same thing. I'm told to turn the remain pusher stud until snug and keep on tapping the pulley and shaft.
Machinist: "Keep tapping. It'll go ting ting ting ting. After a few hours then all in a sudden it will break loose."
Me: "Are you sure? How long will it be 2 hrs, 4 hrs?"
Machinist: "Reasonably sure. No telling how long it takes."

I'm not sure I like tinging the flail mowers for hours on end without knowing whether it'll break for me.

 

[RNeumann]

I've never tapped for hours....maybe 5'-10' before I hit harder or move to another method (heat). That's why he's a machinist and I'm a hack! Haha

 

[CajunRider]

We have that in common Mr Neumann.

 

[flyerdan]

If you still have three holes available to put preload on it, do that and hit it a couple times with one of those inexpensive air hammers from HF. They do an amazing job at getting rusted stuck parts apart without damaging anything. You might have to snug up the bolts a couple times, but once you see it move you've got it whipped.

 

[Stimw]

Rattle it with a air chisel using a flat punch in the tool on a flat surface of the hub in the direction it needs to go. The vibration will get it apart.