gcusmano74

Help me, guys.




I crossthreaded the #7 plug hole.
I remember reading there is a tool that somehow collapses and can be inserted deeply into the hole, and then expanded and unscrewed, rethreading the hole from the bottom, out.
Anybody else heard of such a thing? Where can I get one?



Thanks in advance.............

Indiancreek

No but you can get a kit to put in insert in the plug hole. Made for stripped plug threads NAPA carries them. Aluminum or cast iron head?

doorgunner

I don't know about that. You can buy a thread Tap and "chase" the threads carefully, but you will have to deal with metal particles unless you remove the head to repair the threads

forman

If i remember the chaser has a magnet on the end

7t9l82

i vaugely remember something like that, it was used on 4.6 ford modular motors as they are terrible for stripping out plug holes.
a helicoil or something like mentioned above is your best option.
no , you aren't nuts

7t9l82

what about aluminum heads?

bozzman3

That tool does exist and is good because the threads at the bottom of the hole are usually in good shape so the threads works as perfect guide.

bozzman3

Here you go

bozzman3

A insert is used as a last resort.

croaker

Looks like a winner.

persuader

I like that. Will have to add that to my tool box.

Jeff_Keryk

Are you sure you crossed it? Sometimes anti-seize and other crap gums up the threads. A little WD-40 works wonders...

illenema

This works well! U used it and saved pulling the head I paid like 70$

Iceaxe

I used a back tap just last week to correct a cross threaded plug. It worked like a charm and everything was good to go in less than 15 minutes. The tool was $23 on Amazon. Search Powerbuilt back-tap.

F4Gary

14mm?

Iceaxe

FWIW: here is the email I sent a friend last week.....

Holy crap.... changed spark plugs in the Corvette yesterday and I couldn't get one of the plugs to thread in. I spent about 15 minutes trying to get it started and nothing, It wasn't cross threading, it just would not start. Best of all the plug is one located under the AC compressor so I can't see what I'm doing as I'm working by braille. I didn't want to run a tap out of fear of metal filings getting into the engine. Spent the night not sleeping and having nightmares about having to pull the heads.

Anyhoo..... I found this awesome little tool to repair spark plug threads by back tapping. It worked like a charm and took 10 minutes. The tool works by extending through the spark plug hole and tapping from the inside out.

Powerbuilt Back-Tap Thread Repair Tool