Originally Posted by
scale
I recently picked up a rough shape 91 stumpjumper that i want to turn into a commuter.
The sealed cartridge BB is stuck.....and i mean stuck. I have been soaking it for a few days now in PB. I have a m8x1 sae bolt running through my bb tool into the spindle to keep things nice and lined up and tight as those spines dont seem to like to stay seated. I have been on it with a 12 inch adjustable wrench and no dice. I have even take a 2 foot 1/2 inch drive breaker bar and 1 inch socket to it and used a cheater bar but still no dice moving things on either side.
My next thing is going to be trying to soak it longer and use a impact gun on it. This may sound extreme.....and it is but this thing is STUCK. IT appears to be steel cups and a steel frame. I am not sure how it got so tight.
It got so tight because that's what it's designed to do. BB threads are oriented so that the epicyclic motion of the ball bearings does not loosen the cups, but tighten them. And 24tpi is a really fine pitch for that diameter a fastener, so it can get really tight.
That, and corrosion. (This is why I tell people to use anti-seize instead of grease on threads. Much better at resisting corrosion.)
I assume you're trying to remove the LH cup first. Almost all cartridge BBs have a "fixed" RH and a "free" LH cup It's easier to remove the LH cup first, then go after the RH cup.
Originally Posted by
scale
Anyone know of any place that rents electric impact guns?
I dont want to put a torch to the frame and i am 99.9% sure cola and lemon juice and all that wont work at this point. I have time on my side and am going to let it soak for a few weeks while i either source an impact gun or come up with another way.
You don't need a torch, or probably even an impact gun. Even with steel cups, an impact gun will probably strip the splines on the tool and/or the cup. They're really not designed for that. If it's a steel cup, a heat gun will get it hotter than it needs to be. It can burn the paint off, so keep it far enough away to prevent that, and keep it moving around. Be ready to strike while the iron is hot, literally.
If your cups are aluminum, heat will make things worse, and the impact gun will definitely strip the cup splines. If that's the case, you might want to try a freezing spray/penetrant. I've had pretty good success with them.