Powerbuilt 14mm Back Tap Spark Plug Thread Repair Tool, Straightening Tool, Motorcycle Spark Plugs, Repairs Damaged Threads, Collapsible Design - 640811

Restored the thread of a spark plug hole in my Renault cylinder head which had been lightly threaded a few turns. As other reviewers have said, take your time to figure out how the tool works before going in. I passed it through three times as instructed and needed pliers to expand it because of tight access.

I printed out the 5 star review by HarleyRider, and carefully followed its advice. Result: I sorted out a crossed spark plug thread on my 1972 T series Bentley, without having to remove the affected cylinder head.

Excellent bit of kit reasonably priced and works like a dream

Very satisfied with both delivery, service and quality

effective solution for difficult problem

Brilliant design. Life saver when changing old spark plugs that have been in an alloy head for 25 years! (so the cylinder head threads are not in great condition). Perhaps the whole tool could be an inch longer, but I just used a long 1/2 inch socket as an extension. The knurled nut is a bit tricky to tighten up when you're up to your elbows in engine bay. Nevertheless I managed to chase out 4 spark plug holes on an ML430 where the engine bay is very tight on one side. A couple of the plugs were very hard to get out due to binding with the thread in the cylinder head, but after running this tool through them I was able to screw in the new plugs by hand (before torquing up to 25nm). I still have 12 more to do (there are 16 plugs on that engine!) and I'm considering cutting a slot in the end of the knurled nut so I can tighten it with a flat blade screwdriver. Make sure you apply a smear of sticky grease to the thread tap so that it collects any debris as you wind it out of the head.

Works perfectly 👍

Saved me thousands of dollars and way too many hours. The trickiest part was fixing the threads at the START of the hole as they were the bad ones.. at least this kept crap out of my chambers though, 100% recommend this! It's VERY high quality too, I was impressed. At first I thought the fifty bucks was outrageous, but... nope! This is great for just CLEANING threads as well. So you remove old sparks, put this down the hole, open it up, and thread it out, threads are as good as new!

It help my to rethread spark plug dameged thread on my Toyota prado

Worked like a charm and saved me a few hundred dollars, I cross threaded the first few threads when I tried to to use a thread restorer Because of the restricted hole location, my mechanic wanted to remove the manifold to re re-tap the hole properly. To make sure the tap started straight, I inserted a wooden dowel in the hole and noted the dowel's orientation and then I started the tap as close to this position as possible. So as not to start the tap cross threaded, I inserted the tap so that it's top thread was a few threads below the top and slowly expanded it while gently rocking. It was obvious when the tap engaged properly. I expanded the tap and turned it back and forth. I repeated this, expanding the tap a little at at a time on each try until I needed pliers to expand any further. Then I ran the tap out. After that the oxygen sensor was easy to install.