how do I remove this sprocket?? pics

picassomcp · Jun 11, 2015

I need to remove this sprocket on my haybine to replace the bearing behind it. This is on the upper conditioner roller on a
New Holland 479 haybine. It seems the keyway is wedged in place to hold this sprocket on. There is no setscrew on either
side of the sprocket, seems its just the keyway being wedged in there that is holding it on (that I can tell). I for the life
of me can't seem to get the keyway out. My access is a bit limited but not real bad. I'd like to get to the keyway from the
backside and apply pressure, I've tried that with a prybar, couldn't get much pressure on it, had no luck, even with pounding
on the sprocket while prying. Tried a c-clamp, but couldn't get a good bite and that kept slipping off as I couldn't get onto
it squarely. I've heated it 2x and tried pounding on it to get movement, still nothing. Any other ideas for me to try??? I'd
like to get to cutting some hay here real soon. Thanks for any ideas that you may have.

Scott 730 · Jun 11, 2015

You need this tool. Gib key puller.

Tim(nj) · Jun 11, 2015

Looks like a gib key. Knock the sprocket IN on the shaft and the key will loosen and come out, thus allowing removal of sprocket. If everything is rusted though, it won't be that easy.

picassomcp · Jun 11, 2015

Is the gib key reusable once it is removed?

JMS/.MN · Jun 11, 2015

When you heat it, apply candle wax as it cools. It melts into the seized parts. Ditto on driving the sprocket in.

armand tatro · Jun 11, 2015

Please let us know how that tool works! I made one by printing the picture of it than transferring the shape to a piece of metal and cutting it out. Don't know if the tool needs to be harden or not.I want to think that as you hit it with a hammer it will drive the sprocket away from thekey and the key away from the sprocket. Armand

picassomcp · Jun 11, 2015

UPDATE!! I got the sprocket off, knocking it in was just what it needed. I had to use the BFH (gently) but the sprocket is off. The key looks to be in good shape and I think it can be reused. I can't believe that this key holds the sprocket on without working loose. I really don't see what causes a lock? It must just act as a wedge?? Either way, its a real simple design that seems to work.

Any pointers on reinstalling it? do I put the sprocket on where it needs to be and then drive in the key? or do I slide the sprocket farthur in than it needs to be, install the key, then pound the sprocket onto the key. Does reinstall method matter?

Thanks for the help, you guys are great!

shaun wallace · Jun 11, 2015

Tried making one of them years ago. Made it out of mild steel way to soft. So have to heat treat

Steve@Advance · Jun 11, 2015

Here's how the tool works. Be hard to get it in where this one is located. A chisel behind the head will work too.

www.youtube.com/watch?v=ennQPXoUh8E

T.R.K. · Jun 11, 2015

The key is tapered. Just drive it in with a smaller bfh. be sure the pulley is where you want it when you start.

fixerupper · Jun 11, 2015

Lexion combines still use gib keys. They rarely come loose.

Bob · Jun 12, 2015

My GOSH that video is PAINFUL to watch... over 6 minutes of blibber to watch less than a half-minute of actually popping the key out!

how do I remove this sprocket?? pics

picassomcp

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Scott 730

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Tim(nj)

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picassomcp

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JMS/.MN

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armand tatro

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picassomcp

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shaun wallace

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Steve@Advance

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fixerupper

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Bob

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