Larry Young writes:
> My car succumbed to the loose aluminum flywheel problem this past weekend
> at Hallet. There was no major harm done, it just sheared the bolts and
> slid back on the transmission input shaft. Does anyone have any tricks
> for removing broken grade 8 bolts? I've tried to drill them in order to
> use an easy out, but a standard drill bit doesn't cut it. Any suggestions
> will be greatly appreciated.
If there's enough sticking out, file the stub flat, centerpunch it, then try
drilling with a TiN-coated drill bit (with this, try to maintain steady,
firm pressure--too light a pressure and the coating is worn away). If that
doesn't work, about all that's left is a carbide drill. Carbide will do it,
but it's _very_ brittle and doesn't tolerate bumps or side loads.
In the case of either drill, it's advisable, if the bolt is broken off below
the surface of the hole, to find or make a drill guide. Otherwise, trying to
get a reasonably straight hole into the bolt is rather difficult.
Cheers.
|