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I need some advice, how to knowledge, on using a helicoil for some stripped threads. The first (forward) stud for my headers fell out, leaving part of my AC pump and alternator bracket hanging...and my car sounding like a go-cart. Turns out this is a regular thing with cars that have AC.

Since its the most forward stud, I was told that I can actually fix it without too much trouble...but I am totally unfamiliar with what I'd need to do.

I plan on calling APE and getting a new stud and nut...and whatever I need to hook the AC/alternator plate back in place...but how do I use a helicoil (sp?)?

I'm hoping this is something I can do myself.

Thanks,

Ted
 

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If you're not familiar with using a helicoil, etc, I would recommend that you take your car by a machine shop and see if they can do it professionally, in-situ. They can take a look at it and see if the damage is a good candidate for a helicoil fix. You don't want to use your cylinder head as a teaching device.
 

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Although installing a helicoil is fairly easy, the location of the #1 exhaust stud makes this repair a bit more challenging. Installation involves enlarging the stripped hole by drilling it out, tapping new threads and then installing the helicoil. The special sized bit and tap are included in the helicoil kit. I believe the size kit you need is 8mm X 1.0mm.
To avoid drilling too far, measure the depth of the hole with a paperclip or something. Then put a piece of tape on the bit that equals the depth of the hole. Then drill until the tape is flush with the head.
When tapping the hole, turn the tap about a full turn, then back it out a half turn. This will break off the chips on the new threads and prevent galling. Then turn the tap in a full turn, back a half, in a full turn, back a half. Continue til the tap bottoms out. Ensure that you use only a twisting force on the tap; any side to side movement risks breaking the tap in the head and then the fun REALLY begins.
Instructions on the insertion of the helicoil are included in the kit.
If your unsure about doing this yourself, consider having someone whos done this before do it for you. The 20 or 30 bux may be money well spent.

Good luck!!
 
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