Jul 152013
Powerbuilt 640811 14mm Back-Tap Thread Repair Tool
- 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
The back-tap’s patented collapsible design allows it to engage be placed through the spark plug hole and into the chamber. A mandrel is then drawn back, expanding the tool’s threaded area and threading into the clean threads at the bottom of the spark plug hole. The Backtap repairs the damaged threads as it is drawn up through the spark plug hole, bringing debris and metal filings with it. Made in USA and comes with a Lifetime warranty.
List Price: $ 35.99
Price: $ 21.43
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
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A life saver!,
I didn’t know such a tool even existed until I luckily talked to an auto machinist who told me about this type of tool. I thought I was going to have to pull the (cast iron) head after I started a spark plug wrong due to space restrictions and component interference at that particular plug…then stupidly thought the plug was threaded properly when I went back and tightened it with a ratchet. That only completely cross-threaded the first two lead threads. I discovered my mistake a few months later when that plug finally blew out of the head. I was going to try to get lucky with a 14 mm x 1.25 tap to hopefully clean up the lead threads enough so I could install a new plug (knowing this probably wouldn’t work, but I had to try). I went to the local auto machine shop to see if there existed some kind of an adaptor that would allow me to use a ratchet on the tap since there wasn’t enough clearance above the frame to use the large tap handle needed for this size tap. That’s when the head machinist put me onto this tool. They even had another brand of the tool in stock at the associated parts store, which I purchased…for $91 including tax. Later on I Googled ‘back tap thread repair tool’ and found that Amazon carried a different brand of the same thing which normally retailed for $40 but was on sale for $20 plus $5 S&H and no tax. So I took the $91 tool back and bought the other brand from Amazon. Loosely following the directions, the tool worked like a charm. Two passes through…the first slightly loose and the second with the cutters expanded all the way…and I was able to start a new plug (I had to play with it just a bit to get it in the new groove) and smoothly screw it in all the way to the seat by hand, and then use a wrench to do the final tightening. Problem solved without pulling the head. I had to pull the intermediate steering link to make room to work the tool…which had I done to begin with I wouldn’t have started the plug wrong in the first place. Laziness! One word of caution though…you need to have sufficient good threads at the bottom end for this tool to work and also to retain the plug. If the entire length of the hole is cross-threaded (or if there are insufficient good threads remaining) such as might be the case with an aluminum head, this tool will do you no good. In that case you would have to drill and re-tap it for an insert or helicoil. But it’s well worth the price to have it in your toolbox just in case. Might save you a big repair bill or a heck of lot of work.
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Back-Tap thread repair,
This tool is great! It saved me a huge repair bill. I stripped about 3 plug threads on my aluminum block during a plug change and I used this tool to repair it. It took 3 days to get the tool delivered and about 20 minutes to fully repair it. I just followed the instructions (take your time and don’t fully extend it on the first couple of passes) and before long it was repaired. I hand threaded a “new” plug in about 1/4 of the way in to be sure and finished it with a ratchet and torque wrench. This tool was well worth the money in my situation..
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