AKWhitey

Hi, First post here. Long time reader but now have a question. Number 5 sparkplug treads bad from last service done locally. Plug snugs then free spins. I got ahold of ATD 5410 3-Valve triton insert kit.
Chamfered old threads out and ran rethread tool. While fiddling with an insert from kit i noticed that my Autolite HT-15 plug when threaded into the insert, the actual nut of the sparkplug goes level to the insert shelf.

Spark plug in ATD5410 Insert.
Supposed to be correct kit for 2004 thru 2008 Triton 5.4L 3V.

Read this on a review of my insert kit.
Looks like Autolite HT15 needs replaced by a Motorcraft plug, it must have a wider nut on body.

Reviewed in the United States on May 30, 2017
Verified Purchase
This product worked great. The only thing that you need to know is after you use it, the original motorcraft spark plug for the triton 3v engines uses a 9/16 or 14mm socket and that spark plug will no longer work. Champion makes a 3v spark plug with a 5/8 or 16mm head, you must use this spark plug after installing the new insert into the cylinder head. Other than that it works perfectly i recommend this tool to anybody that has a 3v triton engine that blows a spark plug out!
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