stud at top of hex nut

[philwa]

I am tearing down a 74 2.7 -- I have removed one set of heads and cam towers
according to wayne's book.

On the other side two of the hex nuts that hold the studs have the top of the stud
flush with the top of the barrel nut so I cannot get the allen wrench to bite. I have
no idea how this could happen and not much idea about how to remove the
nut.

any suggestions?

[ajwans]

Centre punch the stud. Left handed drill bit.

andy

[boyt911sc]

Originally Posted by philwa

I am tearing down a 74 2.7 -- I have removed one set of heads and cam towers
according to wayne's book.

On the other side two of the hex nuts that hold the studs have the top of the stud
flush with the top of the barrel nut so I cannot get the allen wrench to bite. I have
no idea how this could happen and not much idea about how to remove the
nut.

any suggestions?

Could you post a picture of the studs? Thanks.

Tony

[Walt Fricke]

I don't know how they could be flush. I know just how they could be so close to flush that your hex bit won't grab enough for removal, though it might have grabbed enough for installation.

If not absolutely flush, you can use chisels and punches and a hammer to build up the edges of the hex socket to the point you can get some purchase.

Drilling out the stud seems a bit crude, and you'd need a long drill. The idea of a reverse twist drill is to unscrew the stud from the case. That would work also, if you can get it to happen,

If you have an air or electric cutoff wheel, as on a die grinder, you could probably cut the stud off down by the case, where it is exposed. If you were able to leave enough of a stub, vice grips might allow you to get the rest of the stud out. Even just a little should allow you to weld a nut on the stub, and use that for extraction.

Here is another idea - there are sockets which are designed for removal of rounded nuts. Their grip faces aren't flat, like a normal socket, but are designed to cut into the nut for grip. I think they are directional, also, as 99% of fasteners are right hand thread. You basically pound the socket like tool onto the nut, then insert an extension and back the nut off. Should work on the barrel nut too. You have plenty to experiment with.

When you put the engine back together, consider using flange nuts of the proper stud diameter and pitch. They exist, and you can use a regular socket. The head is small enough that the socket doesn't bump into the cooling fins. And checking the installed height of yur studs - it is 135mm for a 2.7.

[Flat6pac]

Put a good square cut on a 10mm Allen might well help getting on the set.
Bruce

[David Borden]

My guess is the head stud started to pull and at some point, someone tried to tighten it. They kept tightening and the stud kept pulling till the stud pushed the tool out of the nut ...?

David

[al lkosmal]

+1.......The head studs are pulling out of the case. It is likely time to time-cert (or approved equivalent) the case.

regards,
al

[philwa]

as several people noted someone was trying to fix a pulled stud
and that was the reason for the teardown.

The issue was cylinder 1 exhaust -- it turns out you can wiggle the cam
chain housing off on the left side with heads and cam tower in place so
I was able to get hacksaw to the stud where its exposed on the cylinder
barrel and cut the stud.

My case is a mess lots of material came out with the head studs.

Thanks for the help people.