Stuck bb help

[Splatter Paint]

Re:

Buy the bolt....

 

[ishaw]

Re:

I'm not going to risk damaging the frame. I did experiment this evening and found the crank bolt and a drilled out square of steel holds the tool in place. Using a big wrench (not an adjustable, I'm no neanderthal) and still no movement. I'm not going to risk a big bar for leverage.

It is now soaking in engine oil.

The cable mounting is via the down tube but the bb cable guide bolt is also not moving. Ive been able to fill the seat tube with oil, I'll wait to see what impact this has. At least this has proven there are no cracks in the welds. Only a tiny drip of oil is escaping through the cable guide bolt/hole. Hopefully this will also allow me to remove that too.

I'll keep an eye on it and top up as needed. Would I be better off using gt85 instead of oil?

Patience is not a virtue I have. How long should I wait? My lbs will do it, but this is strangely my first ever stuck bb and I feel I should sort this myself. Everyone else on here seems to have experienced it. I guess I've been lucky so far despite having been building and fettling for over 30 years now (makes me feel old).

Going back to leverage. How much is too much? Surely welds can only take so much?

 

[2manyoranges]

Re:

I have applied a lot of force to a lot of bb and never bent a frame or broken a weld.

Er....just a small check...are you undoing it the right way. Remember that the Drive side is LH thread...

I have a 24 inch socket bar which I use for stuck bb.....used with professional park tool.

 

[ishaw]

Re:

Yup, definitely trying to remove the bb the right way. Will be treading carefully, hopefully no need for excessive force once the soaking does the job I hope it will.

 

[rwm1962]

Not used it myself but on a forum I run seized threads can also be an issue & a lot of the old time fettlers & self reliant mechanics in the USA use a 50/50 mixture of automatic transmission fluid mixed with acetone. Better than any commercial product apparently. The popular off the shelf products are Plusgas, KanoKroil & PB Blaster. I've used Plusgas & KanoKroil & they seem to work well compared to GT85 & WD40.

 

[ishaw]

Re:

Not much oil has dripped through the cable mount bolt so still a lot of oil sloshing around in the seat tube. Resisting the urge to have a go. Will try to hang on until the weekend.

 

[hamster]

Pour a kettle full of boiling water over the bottom bracket outside - anything to get stuff to expand, move and crack corrosion bonds is a good thing.

 

[captaincowelly]

Pour a kettle full of boiling water over the bottom bracket outside - anything to get stuff to expand, move and crack corrosion bonds is a good thing.

Heat is your friend here!Especially as ally is a very efficient heat sink.A couple of heating/cooling cycles using a hairdryer/heatgun/water/the outdoors will help.The heating also helps the oil penetrate further/dissolve corrosion.
For the final attempt,leave it out overnight,quickly apply heat around the shell n try to give it a quick,firm jerk (for want of a better word :facepalm: ).The more flex/play in the tools you are using,the less effective they'll be for the 'impact' effect if that makes sense?
A vice/oppo definitely an advantage.

 

[rwm1962]

Made an error with the M8 bolt I ordered. Pitch thread required is finer than standard. Pitch is 1mm. Correct one ordered from ebay.

 

[ishaw]

Re:

I might borrow a hair dryer and put a few hear cycles through it.

Cheers for the suggestion.