Removing cottered crankarm

[J-wagon]

Hi all, newbie at removing cottered crankarms. Pins removed but the crankarms won't slide off. I've tapped with rubber mallet and tried large flathead as driving wedge last pic but not luck. Any thoughts? Am I missing something? Thx

 

[GTs58]

I don't see a mess of Kroil, PB Blaster or any other penetrating fluid.

 

[J-wagon]

Actually, nondrive success. I just started spinning arm around the spindle and it came off easily. Now trying to figure out drive side

 

[GTs58]

Squirt some PF in/on it and smack it hard counter clockwise with a rubber mallet to get it to spin a bit breaking it loose?

 

[juvela]

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happily this is a fairly rare difficulty

when you have one arm removed as here you can get plenty of leverage for "woggling" by putting a monkey wrench on the pin flat of the side of the spindle where the arm has been removed

be aware for future reference that there are small differences in spindle diameter and crank arm opening;
parts can appear an acceptable fit by eye when they are not

when encountering a machine which has been "worked on" there may be a parts incompatibility...

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just like for almost everything else in cycle work there is a VAR tool for just this purpose -

of course not everyone is prepared to pay a VAR price...

so there are economy gear pullers such as this 11USD fellow available at Amazon:

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[Andrew Gorman]

A gear puller will pop it right off. There may be something goobered up around the old cotter that is keeping it in.

 

[J-wagon]

Well... Not breaking loose with good leverage and above. Might need gear puller

 

[catfish]

 

[J-wagon]

Gear puller did the job.

 

[juvela]

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righty-O! good job.

the tool can also be handy to have about for cases where the removal threads on a cotterless chainset are damaged.

now that you have the arm removed you can have a go at deburring the spindle hole with a reamer followed by a test fit...


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