Started taking the head bolts off. I accidentally started with the wrong one in the back. I was supposed to do the lower one at the firewall, but I did the upper. 10, 9, 8, all went fine, and then 7, that lower one by the firewall, I go to do and I see it is nearly rounded off. I've attempted it with an impact socket as well as a regular socket, all 6 point. It just keeps slipping off. PB Blaster isn't helping, and I've re-tightened the other bolts I unbolted to even the tension.

What can I do? The engine has not been pulled. Will a bolt extractor even fit back there? There's no space to drill, at least with any tools that I have.

This is on a D1, but this sub is much busier, and I think it's the same setup on a D2, if I'm not mistaken. I'm at a loss at the moment.

 

Smash a smaller or an SAE socket on there.

Snap on has a socket with curved teeth thst tighten on the head as you turn. You might want to invest.

Worse case, you might be able to grind the head off, and later remove the shaft with a vice grip.

 

Bolt extractor usually work.

 

I just did that this week, only on one of the middle head bolts. I used a special socket to get it out.
1/2" breaker bar, with a 3' pipe on it, very slow, controlled pressure on the pipe, so the teeth bit.
Worked great, they have saved me several times.
Hold on, I'll take a picture and post it.

 

Bolt extractor

 

You should have enough room for the bolt extractor, shallow 1"+ socket, and 1/2" drive rachet on the back bottom corners. And room for a pipe on either side as well. Not alot of room for rachet travel on either side, but enough to break them loose.

 

100%! That kit has saved my A$$ soooooo many times.

 

Is that the Craftsman set? I don't have any Sears or Kmarts around me, but I got the Irwin kit from Lowe's this evening. I used a 5/8, so I'll try a 15mm and/or the extractor tomorrow.

 

Try the socket first!

 

I wouldn't try a smaller socket before an extractor.
The smaller socket(if it even goes on), only risks rounding it more, and giving less of a bite for the extractor.

Mine is Craftsman, but the Irwin set will be fine, they make good tools too.