Broke rocker bolt off in aluminum head - HELP!

[turbojimmy]

Let's get one thing out of the way - I'm an idiot. Without getting into the difference between pound-inches and foot-pounds, let's say I applied too much force to the rocker arm stud on my 3.1L Buick. The stud snapped off in the head. Can this be fixed? I've resigned myself to the fact that I have to take the head off, but can anyone do anything with it?

TIA,
Jim

 

[blackbuick87]

You have to drill it out and tap it again. It can be done in the car, but would be a whole lot easier if you take it out. Plus you will keep metal shavings out of the engine by taking it off.

Why did you have it off in the first place if you dont mind my asking

 

[turbojimmy]

Originally posted by blackbuick87
You have to drill it out and tap it again. It can be done in the car, but would be a whole lot easier if you take it out. Plus you will keep metal shavings out of the engine by taking it off.

Why did you have it off in the first place if you dont mind my asking

Thanks for the info. I was changing the standard leaking intake manifold gaskets which require removing the rockers and pushrods. Once I was that far, taking the head off wasn't hard. So, I took it off. It's the one at the front of the engine which was pretty easy to get off.

I have another question. The manual, for both the rocker arm and the head bolts, says to torque the bolts to xx and then another yy degrees using tool J 36660. I can simply guesstimate how much further to turn the bolt, right? Like 90 degrees is 1/4 tun?

Thanks,

Jim

 

[Turbo T/A 1543]

The headbolts are "torque to yield" and are supposed to be replaced after one use (although alot of people don't), and I've never had a problem with guestimating the torque values. As far as the broken rocker bolt, if you've got a wire feed handy they will generally come out real easy by welding through the center of a nut to the broken stud and wrenching it out. If it's broken off below the surface more than 1/4" or so I'd try an easy out as it's a little tougher to weld to the broken piece if it's too deep. With a little practice you'd be amazed what you can get out with a wire feed!

 

[turbojimmy]

Originally posted by Turbo T/A 1543
The headbolts are "torque to yield" and are supposed to be replaced after one use (although alot of people don't), and I've never had a problem with guestimating the torque values. As far as the broken rocker bolt, if you've got a wire feed handy they will generally come out real easy by welding through the center of a nut to the broken stud and wrenching it out. If it's broken off below the surface more than 1/4" or so I'd try an easy out as it's a little tougher to weld to the broken piece if it's too deep. With a little practice you'd be amazed what you can get out with a wire feed!

I figured I should get new head bolts, but the manual usually says when to discard the head bolts (I have the GM shop manuals) and it didn't say to in this case. So I called the dealer and the parts guy said they don't replace them either.

I don't have a wire feed handy so I dropped the head off at a local machine shop/engine rebuilder. He scratched his head for a minute and said he'd see what he could do. It sheared off flush with the head and is a very hard material. He said worst case would be he'd switch my hardware over to a core he has laying around. Apparently these 3.1 heads are pretty common.

Thanks,
Jim

 

[turbojimmy]

UPDATE: The local machine shop got it out without having to redrill and tap it.

With any kind of luck, by the end of the day today I'll be exactly where I was this morning on this job.

Thanks,
Jim