Ever remove a Gib Key?
 

I need to fix my friend’s haybine that broke while I as using it.

I bought all of the parts and need to remove a gib key to get a sprocket off to make a quick repair.

Most gib keys are not installed where the sprocket is flush with the end of the shaft like this thing...

I don’t want to bend the sprocket by prying too much. I made a puller using a bolt and it didn’t budge. I don’t want to put heat into the sprocket...

Any ideas?

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"Killer"? Did autocorrect change that from "puller"? A gib key puller is pretty easy to make.

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Autocorrect.

Figured as much. So, you made a puller and it wouldn't budge?

Sometimes the steady pressure applied by a wedge like this won't do it, and it needs a bit of a "shock". Maybe a slide hammer with something that can hook over it.

I have a pinch bar that’s kinda like that and it just keeps trying to bend the key back (this is where having the shaft stick out more would be helpful.

I am considering welding a coupling nut on there and using my slide hammer.

I guess I was typing at the same time as you.

That looks like a rail road spike that's been hammered in. You could try a big dent puller but I doubt you'll be able to move it without using heat but that heat could also weaken the spike. AND if you broke the head off you'd never get it out. (It's not a rail road spike but you get what I mean)

I'd try the puller on its own and see what happens. Just be gentle with it at first.

I've had the most luck with them by putting wedge pressure under the head, and then rapping the back of the head with a hammer many times.
That usually makes a cool sound when the wedge hits the ground and you make up new curse words.
But perseverance should get it.
If that doesn't work, a slide hammer can be cobbled.
If all else fails, weld a strongback to it. last resort.

make your own

https://www.gasenginemagazine.com/gas-engines/a-gib-key-puller

You can heat the sprocket, just not the teeth. I don't see any penetrating fluid. Use some. Or heat it and throw some paraffin wax on the joint while it is hot. That thing is not only wedged tight, it is also frozen up with permanent side load. Heating would help to release that.

I'd be tempted to weld something onto the end of that that I could chuck into a slide hammer.
Wedge it up and then slide away. As has been said, you need to pry and shock. Sam said tap it from the back side, and that would incrementally put a tiny bit of pressure onto the wedge. You want a wedge that is not so soft that it is going to give.

You will win if you are methodical, and don't get crazy. Spray some fluid on it, think about it, and go back later. Every time you work with it, put a little more fluid on.

This seemed like a good solution...

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Still no luck.

Heat it but not cherry red. Just smoke off the paint and let it sit for a while before trying the slide hammer again.

Hit it fairly hard in, that should break up some molecules. Agree with the heat and oil but that's your prerogative.

You may have to up the anti a bit from the slide hammer.

The crankyest fasteners Ive ever had to deal with were the connected link bolts on the track of a tank. We would try with two guys bouncing on a six foot breaker bar on them with no success. Then put those same two guy putting full weight on the bar, and give the link a good whack with a sledge hammer and it would pop lose right away.
Add some heat and its hard to imagine it not breaking lose.

Good luck with it.

Cheers Richard

I can’t hit it without damaging the bearings or bending the sprocket.

I can’t get in behind it at all.

I’m thinking about welding a nut on either side of my slide hammer adapter so I can use bolts to apply some preload then slide hammering.

Heat will be my last resort.

On obvious question but do you have to take it off to fix the problem?

Using the slide hammer isn't doing the bearings any favors either, if there are any ball bearings in there.

Get the paint off of the joints so you get get something in their to lubricate it. I'd heat it up and use paraffin wax. If you're worried about a torch (I wouldn't be) then use a heat gun. Get it at least 300 and get some wax in there. Repeat that a few times.

That sprocket has seen better days, maybe just get a new sprocket, too, and get medieval on that one.

"Hey, (insert friend's name here). Your haybine broke. It's in the way and I need it out of the field. How soon can you come and get it?"

Your welcome.

I understand the need to not damage the bearings. You didn't actually tell us about the bearings —ball, roller, thrust, etc. You can back the sprocket up so that any blunt force will not transfer to a bearing race. Heat, not heat, penetration oil, all of it, you are trying to break a bond. A preferred method is to disturb the bond by shocking it in the opposite direction.

If you go gorilla on that key you're likely to pull it in half with half down inside. Also, tap it up and down, keep shocking it. Always works for me. And unless you turn the sprocket to yellow or blue while heating, I don't believe you're altering the temper. Might want to wire brush the thing bright so you can observe. There's also the trick of turning a compressed air can used for computers, etc., upside down and cooling the key and center shaft.

That key looks pretty stout and you might be able to drill a hole in it. Why? Well, more surface for the freezing technique and an additional pull point. The tools shown are pulling along one edge essentially helping to wedge it further. You want to pull along the centerline. If it's coming out, you won't need to pull the hole apart. It's lots of shocks and minute movement more than pure constant tensile force.

Even another idea is to use the wedge tool and tap the key towards the outside. You will be triangulating the pulling force

Since you are so far into it, how about torching the rod the slide hammer is connected to off of the tube and welding on a 1/2-20 nut. Screw a bolt into the nut and against the end of the shaft.

Like Freiburger says, fix it with fire.

Those keys are fairly soft aren't they? Couldn't you grind it flush, drill it, take a small chisel and release it from the sprocket, pull the sprocket off, and then put a new key in?

Or make a puller by taking a piece of plate steel, drill a hole in it, grind a flat spot to grab the head of the key, drill and tap three holes, insert bolts long enough to contact the sprocket plus some threads and tighten each bolt until the key pulls out.

Turn the gib key into a bolt on the bottom of a motorcyle. It will fall right out.
:)

Connect your stick welder directly to the key, ground on the chain drive. Pulse the machine on/off until the key is cherry red. Spray it with penetrating oil while it's hot.

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Still no love from this piece of 5hit. Heat is next.

I have one of those big pry bars - they are about 6' long and weigh a lot. Somehow if you could get one of those in there along with heat to the sprocket and ice on the key.......

^^^ I started with the pry bar. If I don’t get it, I’m cutting the sprocket to remove it.

The time invested already exceeds the value of the sprocket.

I still think a drill and chisel would get it. Maybe some heat on the head of the pin and let it transfer through the pin. Surprised the two bolts applying pressure and the puller didn't work.

I love/hate challenges like this. I know that feeling of frustration well. Being WAY, WAY beyond any reasonable effort to resolve what should be a simple task. The good news is that is feels THAT much better when you do claim victory!!!

If that sprocket is readily available, I'm in heat first, cut second camp.

Good luck. Keep us posted!

JA

Have you trying changing up the order of the curse words you're using? Or maybe throwing something at it in disgust? :D

You probably have, but have you sourced a replacement gear yet? Seems like 1/2 the time I can find a direct replacement, and the other 1/2 I have to fabricate something.

If you aren't having luck, try talking like this guy when you're working on it. Pure frontier jibberish. He's a trip! :D

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You need to go buy a new sprocket and key. Then give the old key one last gentle pull....it'll probably jump out :D

If you have a tractor supply near you they usually have a pretty good selection of sprockets and such for farm implements.
Good luck
Tony

Sounds just like the agricultural engineers around here!

Sometimes you have to get western...

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Atta boy, Scott...

Did you do the right one?

The upper one looks like it needs replacing first. 😂

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