Removing a cross threaded crank

[jorgemartin]

Hello,

I've successfully removed the (drive side) crank-set. However the left crank arm is cross threaded so badly that the thread is completely gone and can't use the crank extractor.

Any ideas on how to get this left hand crank arm (square taper) off?

 

[Number14]

There is a tool that can do it if they're not completly duff

 

[jorgemartin]

Looks like the TC-8 'thread chaser' is only available in the US?

 

[YahudaMoon]

As your crank is useless now unless you want to refit it ? You could always slot it with a cutting wheel with a grinder. OK your BB will also be destroyed though they only cost £10.

 

[TheDoctor]

There's a number of ways I can think of, but they involve damage to the crank.
Saw the end off and smack repeatedly with a big 'ammer.
Don't saw the end off, then smack repeatedly with an even bigger 'ammer.
Or go for a ride. Eventually the crank will loosen and come off. This may involve damage to you...

 

[jorgemartin]

Do you think smacking the pedal will also damage the BB?

 

[JonnyBlade]

I once over tightened the crank arm onto the BB. When I tried to remove it I only managed to remove the thread from the aluminium crank arm! Enter hack saw and a very sweaty 40 minutes

 

[fossyant]

Hacksaw a slot into it - just avoid your frame. You can also drill a few pilots into it as well

Done it relatively recently when my LH crank on my MTB stripped. Took 10-20 mins to saw through the crank, then off it fell. Got an exact match from SJS Cycles.

 

[JonnyBlade]

I once over tightened the crank arm onto the BB. When I tried to remove it I only managed to remove the thread from the aluminium crank arm! Enter hack saw and a very sweaty 40 minutes

Must have a faster right arm

 

[RecordAceFromNew]

Or go for a ride. Eventually the crank will loosen and come off. This may involve damage to you...

+1, but screw the crank bolt back into the bb spindle loosely, put a strong sticky tape over it (so bolt won't unwind enough to come out by itself which "could" cause damage to you), then go for a honk round the block.

 

[TheDoctor]

Do you think smacking the pedal will also damage the BB?

Almost certainly, but if the BB is OK I'd leave the crank on there!!
Seriously, I've been in this position. It was only when the BB gave up the ghost that I got all medieval and hammery on its ass.
Until then it wasn't a problem.

 

[MartinC]

+1, but screw the crank bolt back into the bb spindle loosely, put a strong sticky tape over it (so bolt won't unwind enough to come out by itself which "could" cause damage to you), then go for a honk round the block.

+1, or get a generic puller like this http://www.24retail....ducts_id=519948.