mhate

Hello all. I'm looking for a little advice with a stuck cottered crank pin. It's on an old Triumph 10 speed (a dump find) that I'm stripping down, cleaning up, and learning on. I've had some fun adventures so far, like removing broken screws from old Suntour derailleurs, but this one's got me beat so far.

The pin on the non-crank side popped out fairly easily, with a bit of Liquid Wrench and one strong tap with a hammer. The crank side pin unfortunately no longer has the threaded part, this has been sheared off. I've tried a hammer and Robertson screwdriver, but no luck so far.

Outside of a cottered pin press, any ideas? Much appreciated.

.Matt.

oddjob2

Google it, it has been discussed many, many times here.

seedsbelize 

I can't speak from direct experience with cottered cranks, but I have plenty of general experience. I would get a drift as close to the same size as the pin as possible and whale away with a big hammer, and plenty of lube. Hit it from both sides, alternately, in an effort to get movement. Heat/cold might also do the trick.

GordoTrek

your situation is a bit different than the norm, the first thing i would do is torch it, wait till it smokes, then tap it out with a screwdriver, of that doesn't work, try drilling through it, then see if it frees up

crank_addict

Just went thru the same. Finish the re-assembly and leave the nasty for last.
Drill through and ride it. At some point, it will shear under a hard mash. Have something ready to poke the remains out, carry a spare or other and ride on.

https://www.bikeforums.net/classic-vi...l#post16735439 post 454 and 455. Good luck

mhate

Thanks so much for all the advice and pointing me in the right direction. I know I'll need to replace the pin anyway, so I may try drilling through it and see if it frees up.

Hudson308 

Looks like you've got the proper drilled plank to hammer against, anyway. Torching the arm and using a BIG mallet against a drift of similar size to the pin as Seeds & Gordo mentioned should do the trick. I'd be careful drilling if you plan to use the original crankset with new pins. How about some pics of the whole bike or more details? Some of those old Triumphs had great graphics & cool headbadge.

arex

+1

It'll budge, but you'll have to convince it to do so. "Violence isn't the answer, it's the question. The answer is 'Yes'."

mhate

Thanks for all the advice. After much sweating and banging with a drift/punch, in the end all it took was 2 minutes with a torch and out it came!

I think I will invest in a cotter press down the line, as I'm anticipating this will also make installing the new pins easier.

Zaphod Beeblebrox 

or just don't use cottered cranks anymore ;-)

autoteacher

In The States we have a store called Harbor Freight where you can buy a chain breaker for $16.99 (Mine was on sale for $14.99) take the screwed in part out, drill the other end out to 1/2 inch, grease up the screw and you have a cotter press. I have used mine for 30 cotters so far and it has not yet failed to remove them easily.

$14.99 or a bent BB shaft or heat damaged chain ring /crank, easy choice.