Gib key
- Thread starter mike4517
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Cedge
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Mike
I tried something a bit strange, the other day, to remove a taper pin which was tightly bound. I was at the local pharmacy and noticed in the wart removal products area, there was a product which is used to freeze them off. I wondered if it might be useful for just such a problem as a stuck pin and I bought a can. Turned out to be a right handy dispenser for liquid nitrogen.
I heated the pieces that were bound and then hit the pin with a bit of the nitrogen. It came out like it had never been stuck. I've misplaced the can at the moment or I'd give you the product name.
Steve
I tried something a bit strange, the other day, to remove a taper pin which was tightly bound. I was at the local pharmacy and noticed in the wart removal products area, there was a product which is used to freeze them off. I wondered if it might be useful for just such a problem as a stuck pin and I bought a can. Turned out to be a right handy dispenser for liquid nitrogen.
I heated the pieces that were bound and then hit the pin with a bit of the nitrogen. It came out like it had never been stuck. I've misplaced the can at the moment or I'd give you the product name.
Steve
B
Bogstandard
Guest
Many years since I have had to remove a tapered gib key, not many used nowadays.
As you said, we used to use an extended drill and tap, screw in a bit of threaded bar and jack it out with nuts and spacers. On many occasions, when there was still a lot of key in there, the thread would strip, then we would drill right thru, with the largest drill possible, to allow what was left of the key to collapse in size due to the taper pressure, and hopefully the flywheel would come off. Never had to go any further than that.
If it is only the last third in there, it should come out very easily, as that part would have very little, if any, of the taper contributing to the locking action.
Hope it helps with your problem.
John
As you said, we used to use an extended drill and tap, screw in a bit of threaded bar and jack it out with nuts and spacers. On many occasions, when there was still a lot of key in there, the thread would strip, then we would drill right thru, with the largest drill possible, to allow what was left of the key to collapse in size due to the taper pressure, and hopefully the flywheel would come off. Never had to go any further than that.
If it is only the last third in there, it should come out very easily, as that part would have very little, if any, of the taper contributing to the locking action.
Hope it helps with your problem.
John
B
Bogstandard
Guest
Forgot to mention, get a bit of diesel fuel in the hole well before hand. That should break any stiction caused by rust.
John
John
I also collect hit and miss engines and have had to remove flywheels and gib keys my fair share. A couple things that have worked for me in the past.
In most cases just inboard of the current flywheel, position is the journal area where it ran in the main bearing. If this is the case, it is much easier to push the flywheel further onto the crankshaft, away from the taper of the pin. This releases the key and then you can do a better job cleaning all the crud off the shaft before pulling the flywheel off.
If you do resort to drilling I take a piece of square stock that fits the keyway and drill a hole thru it in a 4 jaw chuck, this making it into a guide bushing. Drop it in the keyway use a long aircraft drill bit and drill the center out. I havent have much luck tapping them and pulling with a slide hammer, I usually drill successively larger holes until there is just a shell of the key left, them a few hard jerks back and forth trying to rotate the flywheel crushes it down a little and you can press the crankshaft out.
Its never a fun job and when you get ready to reassemble most people drive the new keys in way too tight. It really only takes a couple taps to secure it, I have seen hubs split from driving keys in too hard
In most cases just inboard of the current flywheel, position is the journal area where it ran in the main bearing. If this is the case, it is much easier to push the flywheel further onto the crankshaft, away from the taper of the pin. This releases the key and then you can do a better job cleaning all the crud off the shaft before pulling the flywheel off.
If you do resort to drilling I take a piece of square stock that fits the keyway and drill a hole thru it in a 4 jaw chuck, this making it into a guide bushing. Drop it in the keyway use a long aircraft drill bit and drill the center out. I havent have much luck tapping them and pulling with a slide hammer, I usually drill successively larger holes until there is just a shell of the key left, them a few hard jerks back and forth trying to rotate the flywheel crushes it down a little and you can press the crankshaft out.
Its never a fun job and when you get ready to reassemble most people drive the new keys in way too tight. It really only takes a couple taps to secure it, I have seen hubs split from driving keys in too hard
