Square taper crank removal - stripped threads

carlstone

Help

In a rush this morning I started removing my cranks (never a good idea to rush any bike job) as my bottom braket is goosed. They are oldish Shimano XT square taper jobbies. So I screwed in the tool and took off the drive side crank no problem. Screwed the tool into the left hand crank and started screwing in the splitter inner when I realised the splitter was coming out of the crank taking all the crank threads with it. After a bit of a 'thrutch' I managed to get the splitter tool out of my crank and then realised that the splitter tool was locked solid. This had meant that all the force was going into stripping the threads.

So now I have a crank that needs removing but it has no threads left to attach a crank removal tool. How do I get it out without ruining my frame etc. I'm not bothered about the bottom bracket so have thought about taking an angle grinder to it but that will still leave me with a crank with a bit of axle stuck in it.

Moral of the story, don't rush a job and buy good quality tools ( the splitter tool obviously isn't ).

Pirahna

With a square taper arm you should be able to get a 2 legged flywheel puller of some sort behind the crank arm. Put the bolt part way into the bottom bracket so the puller has something to work against. Get the puller from a hire shop.

They look like this:

http://lazair.com/forum/uploads/post-7-1137868316.jpg

Or carefully cut the crank arm off then take the bracket out.

Monty Dog

You might be able to use a 2-pronged ball-joint splitter like this:
http://www2.toolspot.co.uk/product/5pc- ... m-tool-kit

Monty Dog

Or one of these:
http://www2.toolspot.co.uk/product/shor ... -seperater

carlstone

Cheers, I think I may have one of the two pronged thingies knocking around the garage somewhere.

Gussio

Same thing happened to me when working on the missus' bike. I'd bought the replacement BB from the LBS and the mechanic there kindly rectified my mess free of charge. I was most grateful.

Tom Butcher

You could always smack the crank with a hammer til it falls off - probably risks damaging your frame from the shock but it worked for me - alternatively spray some penetrating oil on it and go for a ride - chances are it'll come loose.

nicklouse

so you are going to refit the stripped cranks?

El Gordo

Tom Butcher wrote:

alternatively spray some penetrating oil on it and go for a ride - chances are it'll come loose.

....but leave the crank bolt in, undone a couple of turns, unless you want a nasty accident.

carlstone

so you are going to refit the stripped cranks?

not sure really. Haven't really thought that far ahead. Can you buy a single 175mm square taper crank that will be a match for the 15year+ old drive side crank. I really don't want to throw another hundred notes at the old bus for a new crank and bottom bracket set up!

Tom Butcher

On a hack I would probably just refit them and get the hammer out again next time the bottom bracket gives up

Are you sure the threads are completely shot - when I did this initially it was because I hadn't screwed the crank puller in far enough - I found I still had enough thread to just about get the cranks off once or twice more. It's a mistake you only make once anyway.

carlstone

Hi Tom

No the puller was screwed right in, unfortunately physics is physics and when you have 16 stone+ riveing on one end of a 12" adjustable something had to give and unfortunately it wasn't the axle/crank join.