Crank case bolt
 

I am trying to split the crank case, but one of the 6mm bolts on the right hand side has been rather stubborn. The rest were fine with a normal socket, but the one at the back is more enclosed. I've tried a box socket over it, but I think it's been a little chewed up previously and my first attempt did not go well. It's the one at to bottom near the rear of the case. Any ideas for getting this out?

Re: Crank case bolt
 

Have you put some plus gas or other penetrating fluid on it?

Re: Crank case bolt
 

I've given it a few squirts of wd40.

Re: Crank case bolt
 

Wd40 isnt the ideal stuff as it isnt a penetrant.

As for the bolt, i'd whack it on the head using a centre punch just to loose the threads. Id also try warming the area around it, if you can

Id buy a deep 6 sided socket that grips the bolt on the faces, not the corners and use it with an impact wrench. I wouldnt use too much force, as its likely to shear.

Re: Crank case bolt
 

I've probably given a bad description. I don't think the bolt will be too stuck, the rest have been ok, but because this was more recessed I've rounded the corners a bit more. I got a box spanner, basically like a very deep 6 sided socket, but it's not really gripping the head of the bolt any more.

Re: Crank case bolt
 

Might have to cut a slot in the head if you can, but I'd still go for a quality 6 sided socket first, a box spanner will always be a sloppy fit

Pics would help

Re: Crank case bolt
 

If it's the long burger that goes through both halves of the case, have you removed the nut from the other end?

Re: Crank case bolt
 

No its not the long one. I'll get a photo tomorrow. The main problem has been that my normal socket didn't fit straight over, but at an angle, it wasn't a problem for the 8 other bolts, but this is more enclosed. I need a thinner socket to get over it properly. At that point it may have purchase enough. Also not a bi-hex.

Re: Crank case bolt
 

Wera Joker spanner might help here.

https://www.youtube.com/watch?v=BvBmCqXDDdk

Either that or a good star socket that'll grip the sides, rather than the corners of the bolt, as already mentioned.

IF it's stubborn and of a small enough size, i've had success with a cordless drill/driver with adjustable torque, and turned the torque up slowly with a suitable socket adaptor attachment, it'll eventually "shock" it free.
Failing that impact driver would be my next port of call.
Alternatively drill it out, buy a new one, use molegrips to turn it out once apart.

Re: Crank case bolt
 

Got a 8mm deep drive with a 1/4" drive, came right out. Thanks for the advice Mavic. I have now discovered that one of my con rod bearings has disintegrated.