Bearing replacement on tiller

[Oguck]

I am trying to replace the rotor shaft bearing on my buddy's bush hog RTS62 tiller. When I went to remove the rotor sprocket this is what I found (see pic). I am unable to just yank the gear off, I have tried drilling the square pin to reduce the metal hoping to get it off but the metal is to hard. Does anyone have any ideas how I can get this sprocket off??????

Thanks in advance.

 

[Oguck]

Here is another pic.

 

[/pine]

I am trying to replace the rotor shaft bearing on my buddy's bush hog RTS62 tiller. When I went to remove the rotor sprocket this is what I found (see pic). I am unable to just yank the gear off, I have tried drilling the square pin to reduce the metal hoping to get it off but the metal is to hard. Does anyone have any ideas how I can get this sprocket off??????

Thanks in advance.

Hard to say with just a pic...but the first thing I would try is a pin punch and a 2# hammer and try to bend or break the key...Then I would use a Dremel (etc.) tool with a silicon carbide stone...

something like this: 84922 Silicon Carbide Grinding Stone / Model: 84922

 

[whis]

looks like its twisted and tried to sear, you need to try and turn it back a little bit

 

[Oguck]

Yea it definitely twisted. Any recommendations on turning it back?

 

[Baby Grand]

A sharp, cobalt drill bit might have the hardness to make some chips out of that key stock.

 

[/pine]

Yea it definitely twisted. Any recommendations on turning it back?

2# hammer... with a punch you just may be able to move it back enough to ease the wedge on it...

Is there any clearance between the sprocket and the casing?

 

[the old grind]

looks like its twisted and tried to sear, you need to try and turn it back a little bit

I'd use a brass drift & a 2lb to do that also (sharp raps, not heavy sledge-hammer blows), ... maybe jam the big rock back into the tines to keep the shaft from rotating. The key will be plenty tight after being distorted, but a claw puller should be able to muscle it off from there. (big 3-jaw or beam, no slide-hammers indicated.)

You may have found by drilling that key-stock work hardens easily if it gets hot enough. Cobalt might get over that but not easy working that small. (~3/16"? small bit, lotta pressure required, and done 'wet' to keep cool)

Any metal can be ground if you can get into where you need to. btw, I asked my dentist about those tiny burrs some years ago, knowing they're never reused, and he's handed over every one he's used on me since. (carbide for teeth & gold, diamond for ceramics/crowns, 1/16" shaft/collet)

 

[Stimw]

Turning it back for sure.
I would take an air chisel and get a bite on the flat side of the sprocket and try to rattle it back after blocking the shaft from turning.
I get a lot of things loose/apart with an air chisel. I even have a flat ended bit for some uses. The trick is to do it without damaging parts.
My nephew was trying to change rotors on a Honda Car, it had screws securing them. It had Philips head screws holding them on. He tried for hours, even bought an impact driver and finally brought it to me. It took me 10 seconds to walk the first one out with the air chisel! I let him do the rest for the practice.

 

[lmalcomb]

You are exactly right about the air chisel, I cut a bit of to have a flat one Myself.