I snapped off an exhaust manifold stud on my '85 765. I've real all the FAQs and want to do it without removing the head. I just don't feel confident about drilling without some kind of fixture. I have a concept for a tool but don't have a machine shop. If someone with a welder wants to make one I can surely test it. It may be commercially valuable - don't know. This tool idea could work on lots of different brands. Any takers?

cheers - dave

I'm afraid you will find you need to remove the head and take it to the bench or a machine shop eventually. Which really isn't too hard. But will cost you a head gasket kit + having the head planed.
As an alternative, a guide made from a cut-down exhaust manifold could be a really successful thing. The hard part of the job is keeping your drill straight at the somewhat odd angle of the side of the head. And you'll probably find that you need a right-angle drill so you aren't banging into the fender.
So a guide which can be bolted to the existing studs and keep your bit out of trouble when drilling would be a good thing.

For future reference, when removing nasty exhaust manifold bolts, soak them with PB Blaster, then split them with a chisel. It's not necessary to cut them all the way through, just spread them open a bit so they unscrew easily.
New copper nuts from Volvo or a hardware store are the right replacement.
Rob Bareiss, New London, CT

What do you mean, "split them"? Could you please explain. I have to remove my exhaust manifold, and I just want to be "armed" with all the info I can get (in case I encounter the unexpected).

Thanks,

Jeff Pierce
--
'92 Mercedes 190E (my daily driver), '93 945 Turbo (a family car w/spunk), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece)

details please
--
http://www.fidalgo.net/~brook4/oilslubesfilters.html