mds...
Broken Rocker-arm bolt
Thread Starter
Intermediate
Joined: May 2008
Posts: 41
Likes: 3
From: Palm Springs CA
Broken Rocker-arm bolt
My 71' has a broken rocker-arm bolt. It sheared at the pivot point, so about an 1/8" of stud is sticking out.
What do I need to do to extract that stud? Am I right in thinking it is pressed into the head, not threaded in?
I do not want to pull the head and take it to a machine shop unless I absolutely have to.
Please advise.
Thanks!
What do I need to do to extract that stud? Am I right in thinking it is pressed into the head, not threaded in?
I do not want to pull the head and take it to a machine shop unless I absolutely have to.
Please advise.
Thanks!
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
The trick will be getting enough of a grip on it to pull it out. Once you get it out, installing a new one is no deal. If it was (or is) a screw-in stud, slap a wrench on it and turn left.
Burning Brakes
Joined: Nov 2005
Posts: 1,137
Likes: 51
From: Cartersville GA
I would just go ahead and pull the head and take it to a machine shop. They would probably drill out the old stud and replace it with a screw in stud. I think trying to do this with limited tools at home would be a real headache. Unless of course you have the right tools and knew what you were doing along with patience and time to spare. Plus they could check the head to make sure there isn't any other damage that might have been caused by whatever broke the stud in the first place.
Pro
Joined: Oct 2005
Posts: 505
Likes: 8
From: Houston Tx.
First, file the end of the stud smooth. Carefully center punch the stud in the center and drill through the stud with a tap drill for a 10-24 or 10-32 tap (I forget the size). Tap the hole in the stud. Get a fender puller/slide hammer and replace the sheet metal screw with a steel machine screw. Attach the fender puller to the stud and work it out with the slide hammer. If the stud won't move, then it is machine shop time. That is how I removed them back in the 70's when I did that sort of thing for a living.
Melting Slicks
Joined: Aug 2005
Posts: 2,359
Likes: 15
From: Confusion
My friend had a Chevy 350 in a boat, the kind of setup where the water ran through the exhaust manifolds. He was running and lost power, after removing valve cover for him, the rocker stud was pulled out of the head. Long story short, the cooling jacket rusted through in the exh. manifold and water got back into the exhaust valve, the one rusted/seized up tight and when push rod came up to pivot rocker arm and the valve didn't move it leveraged the rocker stud out. We removed head and had a machine shop check it out and ultimately he had to get new exhaust manifolds also.
Something in your engine caused the stud to snap, that is not from normal wear. Just something to think about.
PS---Also be careful with the above method of drilling and removing with an EZ out. If that EZ out breaks off in the stud, you are F---ed, then you will have to remove head and haul it to a machine shop. JUST BE CAREFUL
Something in your engine caused the stud to snap, that is not from normal wear. Just something to think about.
PS---Also be careful with the above method of drilling and removing with an EZ out. If that EZ out breaks off in the stud, you are F---ed, then you will have to remove head and haul it to a machine shop. JUST BE CAREFUL
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Verdad Gallardo
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
You need to analyze the broken surface of the remaining stud to determine what caused it to fail. If you can post a photo of the broken stud surfaces, we can give you a 'read'. Basically, if those surfaces are very rough and jagged, it is likely an "instantaneous" fracture and there was some finite point of failure when it broke. That would indicate something else bound up and you need to locate the problem and fix it before you go back together. If the surface has only a small area that is jagged (where the stud finally snapped), but most of the surface has a 'smoothed-over' appearance, the part has been working a long time to fail and is probably a bad stud or it was damaged during installation and finally fatigued to point of failure...not likely to have another source for the failure. It's important to know which so that you can resolve the source of the high-stress condition.
