Saturday, March 20, 2010

Broken bolts/studs?

There are various ways to remove them and this turned out to be an exception to the normal rule.  Usually we are stuck with a seized thread, due to corrosion, and the fastener duly snaps off in the engine, frame or whatever.


Now this particular bolt wasn't seized, but its thread was damaged and it wouldn't attempt to unscrew.
 

The easiest thing to do was cut it flush and drill through it.



So, armed with the necessary, a centre pop in the middle of the stud, a small drill bit (3.5mm) for a pilot hole and we were away.


The idea when drilling through a stud is to be dead centre and continue that way!  If this was in a cylinder head, or equally important part, I'd be a lot more careful. 


 As it happens I went off at an angle, but this proved to be to my good fortune!


The stud could now be closed up with a Vice Grips and popped out of the frame with a punch and hammer without any further damage to the frame.


An 8x1.25mm tap to re-cut the thread.  There is a good chance that it's too far gone for this and may need a thread insert fitted, but it's worth a try anyway.


Yes, the thread is too far gone for my liking.  The bolt will screw in but has a touch too much play.  It would work for a while but will strip at some point.  Time for a Recoil kit and the next blog post.