Time to change sprockets and chain but the front sprocket won't budge !! It's an 88 but hopefully someone can help me solve the problem. Used an impact gun, then a breaker bar and finally heated the nut but this thing wont' move.

 

jeebus that thing is just wow!
http://www.sharenow.com/blog/post/484/

 

I've changed a lot of sprockets but this one has me baffled. I've thought of taking a cut off blade on a dremel and splitting the nut but that may not work.

 

im thinking you need a real impact. (the kind that you hit with a hammer)

 

 

or spray it a couple of times with some wd40. use a wrench and crack it with a hammer while you try to break it with the wrench

 

try some penetrating fluid on it, then tighten and loosen it with your impact to try and break the rust free. Just out of curiosity, what psi are you running your impact at?

 

Its an electric impact gun. I've removed lots of stuck bolts with it but not this one. I do have an big impact that you hit with a hammer. I'll try it next. I am soaking it with PB Blaster.

 

an electric impact only has about 200ft lbs of torque i think, you need an air powered impact. That will bust that rust for sure.

 

I used an impact screwdriver and a few good whacks with a hammer and it came undone.