Features:

  • Back-Tap's patented collapsible design allows it to engage be placed through the spark plug hole and into the chamber
  • The Back tap repairs the damaged thread as it is drawn up through the spark plug hole
  • Made in USA. Meets or exceeds ANSI standards.
  • Back-Tap 14 millimeter thread straightening tool for spark plug fouled threads
  • Collapsible design allows it to engage be placed through the spark plug hole and into the chamber
  • Expands the tool's threaded area and threading into the clean threads
  • Backtap repairs the damaged threads as it is drawn up through the spark plug hole
works exactly as advertised fixed 250,000 mile junkyard turbo LS spark plug threads

Every 10 junkyard LS motors or so i get one with chewy threads at the top, and i have no finesse at all, so chasing or re-tapping is just asking for me to butcher them more than they already are. Recently i had the dreaded, spark plug threads endlessly and never gets tight, so this time i was ready to buy a tap\chaser solution, started searching and found this figured i would give it a try. Extremely impressed with this, used it while the motor was in the car before i went to the dyno for testing, lightly greased the tip to catch material, and installed, expanded and backed out, in minutes i had clean threads that tightened up nicely. at 20 dollars its worth it even if it were one time use

This Works and Shipping Was Fabulous

I damaged a thread in the block while inserting a plug in an aluminum head...rather than use the traditional tap and drive the shavings inward, I searched the internet and found this backtap and decided to give it a try...I needed it quickly so took one day delivery...it left pa at 6:30 am on friday, trucked to memphis, flown to grand forks ND, driven to bemidji, mn and trucked to my home in walker, mn...amazonly, all in 30hrs..I still cant believe that...anyway the tool is very straightforward and easy to use...just take your time and increase the cutting pressure only slightly as you go..on my situation, only the first row or two of threads had an issue..i think the threads got folded over when i applied pressure to the plug as i was trying to get it started..anyway did put alittle bit of grease on the cutting threads after each pass, cleaned off the old grease after each pass..I didnt start the threads all the way thru...I went about half way thru and tightened up the adjuster slightly just to feel it was in place the worked it back...its very easy to get a feel and use...with each pass I tightened it up more and after about 5 passes the tool felt very stable in the thread and low and behold, my problem went away...I put in a new plug with some antiseize and am back in business...when this inially happned all i could see was a head removal and a 2000 dollar bill...thanks for a great tool and a very big thanks to amazon for your great service..I will continue to use your site...craig

Tool works as advertised, seems well built (did not fail when on trial) and was more affordable than the alternative.

Recently purchased a 1986 Nissan Pickup with 138,000 miles on the truck and engine. I was going through the motions of familiarizing myself with the engine and systematically pulled the plugs to check general health of the engine. The plug in cylinder 3 was cross threaded! Rather than pull the head, I researched what others had tried in similar situations and found this useful tool. I like that it started at the bottom of the bore where the threads were good (hopefully), worked upward capturing shavings (hopefully) and systematically cleaned the threads. Purchased one with high hopes. I approached the task patiently ( and with a lot of grease) eventually working up to the full 14mm cutting range. I found after several passes, from bottom to top, that a burr had formed at the top of the bore and would not allow me to thread a plug in at all. I reinserted the tool and worked in an up and down motion through the bore. This method cleared the burr and the plug went in successfully. Phew! About one hour of effort and the truck is running better than ever. Tool works as advertised, seems well built (did not fail when on trial) and was more affordable than the alternative.

Saved me time & money but was harder to use than expected.

This reverse tapping,"thread chaser" worked almost exactly as described. WHAT I WAS UP AGAINST: I had a partially damaged spark plug thread, in what I presume is the usual position of near the "top-lip" of the spark plug shaft, caused by a previous owner who I think tried to screw in a spark plug at an angle with some kind of air powered socket wrench. The cross-cut thread damage done by this resulted in every attempt to screw in a spark plug ending with the engagement of the mis-aligned cross-cut threads that were created by the previous owners poor alignment job. On this damaged helix track of threads you'd get maybe 1-3 full 360 degree turns of the spark plug and then be greeted with the full seizing of the process. When faced with the alternative excessive method of repair, as what I had was, what would still be described as 80% of entirely undamaged threads. I went with this ingenious "thread chaser" as I really did not want to start completely drilling out all the existing spark plug threads, then re-threading that shaft & then go putting in a "helicoil"/"timesert" insert,(Not least because of all the swarf it would create, as I would also be faced with not being entirely convinced I would be able to drill out the spark plug socket without first having to take the whole engine head off, [to ensure the hole drilled would be at the correct angle etc.] Moreover I've also read that helicoil inserts can interfere with the combustion chamber chemistry resulting in knocking/detonations.) IN USE: It took me more than the 4-5 passes that are suggested on the packaging to fully "re-thread" the damaged section. While progress was slow and I must have done 10 passes from the bottom up, primarily all by hand-twisting this reverse tapping tool, with only slight assistance from a socket wrench(torque lever) during the last 3 passes. With the rationale behind this being that I was seriously concerned, that this thread chaser would not engage with my existing threads and instead cross-cut/damage them too, if I relied too much on brute force. So I used the least amount of torque possible, hand-turning for the majority of the time and just gingerly applying my socket wrench when I was fairly confident that I had engaged my pre-existing bottom threads and was just about beginning to start bumping up against the damaged section that needed re-tapping. For example, there was one hand pass that I was doing were I felt I hand encountered resistance far too early(meaning I was just about to cut into fine pre-existing threads) and I simply backed out and started again. With no issues. If I had been using my socket wrench, you can imagine that I might not have felt that, this was the case, until a little cutting damage had already been done. I would also advise to check the torque/tightness of your spark plug on a daily basis once you're finished and driving around again, as it the plug might work loose & may especially need re-tightening after the first days travel. Mine didn't, but better safe than sorry for you high compression ratio gearheads out there! I was also thinking about applying some Loctite 620 or Permatex High Strength Sleeve Retainer which are designed for these kind of environments, to the top 20% of loose re-cut threads, that is, if I ever grew concerned for the pressure handling ability of just 80% of threads. It is a pity that the designers of this tool "powerbuilt" don't recommend a thread sealant!

Budget Saver. Great Product

Purchased this tool to rethread a spark plug port on my son's 2008 Mustang. We had tried a top-thread limited access tool but just couldn't get it to bite. I was busy one afternoon so my 16-year old son decided to tackle it himself...without telling/asking me. When I got home that evening, my son greeted me with a grin and said, "I fixed the Mustang." I tell all this to show how well and easy this tool worked. My 16-year old with limited mechanical experience was able to easily fix his car. Needless to say, I am a proud Dad. Thanks for a great product.

Money Saver

Purchased a old motorhome that appeared to have the original spark plugs in it. 25 years left the threads a little rusty, and on one occasion prevented a new spark plug from full insertion. This unit helped save me, especially a lot of money. It cleaned out the holes and thread successfully. Most importantly the majority of the debris is directed outside the engine compartment which makes clean up easier. Some tips I would recommend is to go slow, I ran the unit through the treads a half dozen times. The first few times I did not fully spread the tap and then the last few time I ran it through fully open. I also kept lots of lubricant on the tap to help with debris collection. (I use WD-40)

If you thought your life was over, this tool gives you hope.

I've never written a review on anything in my life. I've never even stayed on the phone to give a review of the customer servicer... but, this little handy thing molded me into a reviewing expert and you must know about it. Here's my situation and I can only assume it's nearly yours: I have a 2010 Ford Explorer XLT on which I have done the maintenance myself. Never a big deal, any idiot can change oil... I thought any idiot could change plugs too but apparently I'm a special kind of tool. Brakes done, filters all done, belts done... you get the drift. There I am jamming to my 80s classics and got 4 of the 6 plugs replaced along with their cables. Psh... this is easy. Then, everything changed. I can always tell you where I was when I cross threaded my spark plug insert. 5th one out but no matter what I did, I could not... COULD NOT... get the new one in. Heck, I couldn't get the old one back in.... simply would not catch. Hours I spent out there learning and creating new profanities and tying them together like a drunken sailor... I'm just happy my 3 year old wasn't there for this. As you know, it wasnt even my fault. Who uses aluminum heads? I mean, who cares if they are ligher, promote combustion, easier to produce, cheaper... all dumb excuses when one can cross thread the insert. Should have been steel like the "good old days" (that I dont actually know about). All my prayers went unanswered... I tried to ask all of the Heavenly Host for help, "If you let this in, I'll stop... (well, you don't need those details). Nay, it wasn't meant to be. To AutoZone I said... and my wife's chariot escorted me to the land of all the answers... "helicoil"; "go to Ford"; you're SOL"; "giggles". Any of these answers are expensive or time consuming. Hours of internet searching... nothing. After several conversations with my earthly father... (an actually smart aircraft mechanic)... he found this gem. Hope. The glimmer was there when I watched the videos and saw it in action... easily ordered it. Here in two days. I've spent so much money on things I dont remember, things I may be ashamed of... we all have. This though, this magical little piece of American ingenuity... this is the best $30 I have spent in my entire life, per capita. Even better than that one time in the Philippines. I put this "save the day" tool in, expanded once and it caught immediately. I reduced the size (simple) and greased it up... ran it through the insert three times expanding it more each time and cleaning it after each use. "Here goes nothing" I said... the new plug found its way home on the first tuen. No resistence... it was finally accepted. Just like we all want to be. Maybe that was my prayers being answered. Maybe this is just how life is. But I'm going to take the ATLEAST $1970 saved thanks to this tool and donate to a good cause... Hope is what we need. This tool does it. Even if you dont need it, buy it. Buy it for that hope. Because if you ever need it or, even better, a friend needs it... you will never hear the end of your greatness. And acceptance. Off to drive.

Saved my head.

Friend was helping me put in plugs and apparently doesn't understand how to put in a plug :( After he stripped it I thought I was going to have to use a helicoil and those things are a pain in the*** and never work right. This thing saved me. I was able to un-screw (pun intended) the stripped threads and get the car back on the road. Side note: It would be a little better if it wasn't so hard to expand the threads once its in the head.... working on a 2012 Subaru with an H4 block made it difficult but trying to hold the shaft while screwing the expansion bolt with your fingers in a area the size of a cereal box. Literally took an hour just trying to expand the tool far enough to re-work the threads. But nonetheless awesome tool worth every penny

Saves time, saves money, avoids headaches

Great product. I can’t say enough good things about this tool. The previous owner of my Explorer 4.0 SOHC (2000) had either never replaced spark plugs or had already cross threaded them when they did replace them. By the time I got them out, the threads were toast. This tool allowed me to properly re-thread all spark plug holes and avoid very costly repair bills at the mechanic. Reviews stating that this is junk are most likely from those that did not use the tool properly and take time to gradually increase the diameter of the rings pass by pass. I took about 7-10 passes on each plug; take your time and be patient. Use enough grease to cover the threads to extract any shavings created by the process. If you can be patient and do not rush this fix, this tool will really impress you.

Great tool! Tebowed soon after job was done

Stripped cylinder #2 on my Ford Sport Trac. Dreaded the fact that the engine had to be pulled. Youtube some threading option, and came across this. Shipped within two days (ordered Friday Night, here by Sunday Afternoon). Cylinder #2 has a small space to work with, having to take the passenger tire off for easier access. Followed directions, put it straight through the hole, expand it, back thread it 3x. Patience is needed with this, especially when it started getting tougher to turn, which I backed it out, greased up, and went back for some more turns. Overall, this $25 tool saved me about $2k. Great tool! Tebowed soon after job was done!

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