Can't move crank from driveside bearing

[phil23fair]

I'm stripping down a GP150 to replace the driveside oil seal. By the way the stator plate and mag flange came apart I'm guessing this has not been done for a very long time if ever. I've got everything apart now except removing the crank from the drive side bearing. When I've removed crankshafts before, normally a tap from hammer with a lump of wood on the end of the crank is enough to move the crank. Not in this case it is solid. I don't want to damage the crank if I can help it, but a 2lb lump hammer and a block of wood and a great deal of effort from me only succeeded in splitting the block of wood. Have any of you suffered this problem and if you did how did you get ther crank out without damaging it?

[fairspares]

you should never hit the crank especially if you want to reuse it , there is an extractor tool you should use.
http://www.ebay.co.uk/itm/LAMBRETTA-CRA ... 0649724098

[nelson pk]

Yep, buy the extraction tool and then send the crank off to get it balanced/trued properly after hitting it with the 2lb lump hammer

[drunkmunkey6969]

Use a bigger hammer..... Lol ;0)))

[phil23fair]

Thanks for your replies and I would have used a bigger hammer if I had one but it was cheaper to buy the crank extractor than a bigger hammer which I have now done. I appreciate knocking ten bells out of a crank is not recommended, but this one has only got one more journey to do. I have bought an Indian GP import as a project bike and it is remakably good condition with only a small amount of work to get it MOTable which I have decided to do and get it registered before our local DVLA office disappears. The biggest problem being the horrendous clouds of stinking white smoke when I started it hence the need to remove the crank and replace the drive side oil seal

[dirtyhandslopez]

Call me stupid if you want, but how is hitting the sprocket side of the crank going to alter a crank if there is no resistance on the other side of the crank?
Now, it dropping on the floor after you hit it and it flies across the room, would be understandable . Not that that has ever happened ever, anywhere
If the crank alters by hitting the sprocket side with no resistance on the other side, there would be something wrong with the crank in the first place.

[Grumpy225]

I agree with Lopez here. Have always threadded an old sprocket bolt in to the crank and just tapped it out of the bearing. Don't wang on it, just steady taps and I've never had one not come loose and don't let it fall out of the case. Always replace the bearing since the race isn't supported when tapping the crank out.

That being said the more motors I build the less the hammer gets used. I've found specific tools for specific jobs makes life easy (and who dosen't like extra tools?!).

[nelson pk]

Call me stupid if you want, but how is hitting the sprocket side of the crank going to alter a crank if there is no resistance on the other side of the crank?
Now, it dropping on the floor after you hit it and it flies across the room, would be understandable . Not that that has ever happened ever, anywhere
If the crank alters by hitting the sprocket side with no resistance on the other side, there would be something wrong with the crank in the first place.

Because you can very easily knock it out of true...... bearing in mind that a crank is trued on v blocks with dial gauges by the use of a hide hammer or similar. So if you tap one end of the crank without holding the flywheel of that side of the crank that you are tapping in say a soft vice , you can move the cranks flywheel very slightly on the pin. It wont just suddenly break apart but it will be out of true.

[camel]

try using a copper faced hammer straight onto the crank,forget your block of wood its absorbing the energy

[joespeed]

cranks are a little sensitive,hammers were the only thing available 30 odd years ago they came in many shapes and sizes,things are different now ,pull the crank in push the crank out no hammers copper,hide sledge or claw hammer needed!