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Dr. Hamman
Dr. Hamman, Automotive Engineer
Category: Car
Satisfied Customers: 6286
Experience:  30 years experience, Repairing, building, & designing, automobiles.
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What is the best way to fix a striped out rocker arm bolt ...

Resolved Question:

What is the best way to fix a striped out rocker arm bolt hole in a aluminum head?
Submitted: 8 years ago.
Category: Car
Expert:  Dr. Hamman replied 8 years ago.
Hi, I will do my best to assist you. When you are finished please click on accept. I don't get paid unless you do. I don't know if you are a pro or a novice so we may have to fine tune the answer.


The best way is to install an insert, it is stronger than the original threads. Check out this link, it shows photos, and goes through the process in detail. If you have any more questions I am here to help. Good luck, and Thanks for using Just Answer.

http://www.muller.net/mullermachine/howto/insert/index.html

I hope this helps, 100% satisfaction is my goal. If the answer is not clear, please reply and I will assist you more. When you're satisfied, click on accept. I don't get paid unless you do. A bonus and positive feedback are always appreciated, good luck and Thanks.
Dr. Hamman and 2 other Car Specialists are ready to help you
Customer: replied 8 years ago.
Reply to Dr. Hamman's Post: I an a fairly skilled mechanic, but I did not notice the bolt hole was striped out until I already installed the head back on the block and torqued to the proper torque spec. As you would guess, it was the last rocker arm bolt hole that striped when I tried to torque the bolt to the proper torgue spec. I would have to pull all the rocker arms and the head back off to machine as in your answer. Is there possibly another fix to my problem?
Expert:  Dr. Hamman replied 8 years ago.
You can put grease all around the hole. Drill it out by hand with a power drill, then tap it, and install the insert. The grease will catch the chips. This is the best way to fix it. The other ways include welding it up then re drilling and retapping the hole, and oversize studs. The insert is the only way to go. I have done them all. It is easier and better quality too. If you have any more questions I am here to help. Good luck, and Thanks for using Just Answer.

I hope this helps, 100% satisfaction is my goal. If the answer is not clear, please reply and I will assist you more. When you're satisfied, click on accept. I don't get paid unless you do. A bonus and positive feedback are always appreciated, good luck and Thanks.
Customer: replied 8 years ago.
Reply to Dr. Hamman's Post: This is worst case. The bolt hole that striped out is the last rocker arm that sits all the way back almost against the fire wall. I cannot get a drill even close to the hole beacause of the firewall. Any other ways, Possibly epoxy or am I going to have to pull the head again?
Expert:  Dr. Hamman replied 8 years ago.
Hi, I will do my best to assist you. When you are finished please click on accept. I don't get paid unless you do. I don't know if you are a pro or a novice so we may have to fine tune the answer.


There is no epoxy that will do it, if any one tells you there is they are wrong. Ok I tell you what you do is you get an oversize stud. And tap the hole out to the next oversize. You should be able to get a tap back there. I think small block chevy rocker studs will fit this, and they make those studs with over size threads on the bottom. If you can get one of these (hot rod shop) and get a tap in back there you should be able to pull this off. If not then the head will have to come back off. If you have any more questions I am here to help. Good luck, and Thanks for using Just Answer.

I hope this helps, 100% satisfaction is my goal. If the answer is not clear, please reply and I will assist you more. When you're satisfied, click on accept. I don't get paid unless you do. A bonus and positive feedback are always appreciated, good luck and Thanks.
Customer: replied 8 years ago.
Reply to Dr. Hamman's Post: Last question. The rocker arm has a bolt, not a stud. If I go with a oversized bolt, it will not pass thru the rocker arm. Looks like I will have to pull the head back off. I appreciate you help. Any further ideas?
Expert:  Dr. Hamman replied 8 years ago.
Use a stud that is larger on the bottom than the top, they do make them, be sure it is grade 5, or 8, and put a nut on it. This works well if you know what you are doing. If you can't find the pieces, pull the head, good luck, this can really be a pain.

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