Getting tapped, you’ll need to insert tap far enough so the full diameter threads of the tap engage the stripped plastic threads. You can feel this happening. Don’t go too far in. Click images to enlarge.
I have stripped the Dynafit rear binding unit spring barrel cover (cap) threads more times than I’ll admit. Sometimes we’ve effected our ski touring binding repair by carefully inserting the barrel cover and getting it to eventually engage the housing’s plastic threads with correct alignment. Other times the bindings were replaced. In any case, with several decades of this involving myself and others here at the WildSnow shop, I’ve got quite a box of ruined heels. It is time.
One of our esteemed commenters asked about thread tapping the stripped heels to give them new life. I’m not sure why I didn’t do this sooner, but any time to begin something important is better than not beginning. The process is not rocket science but requires hand skills, and best, a bench vise to hold the tap. The challenge is getting the plastic heel unit to begin threading perfectly straight and not following any threads you’ve bunged up. I found that going slow and eyeballing alignment from different angles was the key. So, for around $17 perhaps you can repair a binding worth several hundred.
Required tooling: 20mm X 1.5 Metric HSS Right Hand Machine Tap.
Messed up threads.
Solution.
Result.
Technical note: Some Dynafit spring barrel caps have a slot-cut in the threads that’s probably intended to help the cap thread easier during first install, or perhaps intended to provide a bit of “thread locking” effect. Problem, this small slot makes the cap act somewhat like a tap, thus making it even easier to cross thread. If your barrel cap has the slot in the thread, be extra careful installing after you think you’ve tapped and renewed the plastic housing threads.
Safety note: As always, this mod is at your own risk, and inspect any ski binding before every use. In the case of classic tech bindings, pay attention to the rear spring barrel, that it isn’t gradually backing out or loosening, and remains on the release value setting you intend. We suspect this could be a problem with some Dynafit as well as other brand tech bindings, especially when adjusted to lower settings. Clearing (chasing) the threads with a tap could exacerbate this occurrence as doing so causes to spring barrel cap to thread quite easily. It could be that a thread locking compound should be used. Over many years, we’ve not found that to be the case, but we’ve not run many bindings at ultra-low tension settings, and when we have run at low settings (as with children) we’ve not had any trouble with the spring barrel cap.
15 comments
” I’m not sure why I didn’t do this sooner, but any time to begin something important is better than not beginning. ”
probably becuz like me you didn’t think it could be done, good work !
A much needed technique, very cost effective. Like all of us, I wish i had known about this before buying replacement heel pieces. Great tip from Braden and Lou!
Lots of this style binding around, millions, literally. So I figured better late than never on posting this fix. Lou
The picture alone is a worth visiting this site. A real eye catcher.
I love reading hot rodding magazines just for the cool stuff they buy and then proudly mess with it in mind expanding ways. But I don’t own a hot rod. Just sporting gear.
And here it is. Together.
Thanks for existing wild snow folks.
I would not use Loctite – as it seems to do bad things to plastic and the last thing you want is a heel piece blowing up in a bunch of pieces. I started using Vibratite on things that interface with plastic, at the recommendation of the Binding Freedom insert makers – and it’s an awesome product that might work well if you have trouble with a barrel backing out.
Impressive. I just rammed them in ghetto style. This seems much more refined
Ah! Where was this post 2 weeks ago when I spent 2 hours with a tiny file trying to fix my threads? (FYI: filing the threads will actually work, but it is tricky because the process requires more than one beer, but you do need to keep a steady hand.) But, this is great. Thanks.
Robin, there are dozens of types of Loctite, the correct one is specified for plastic. That said, I’d not bother unless I observed a tendency for spring barrel cover to loosen. Likewise, if there is a variety of Vibratite that’s specified to work ok with plastic, then great. Lou
The Vibratite for plastic seems fairly effective in my limited experience. I’m interested in trying the Loctite 425, but at $30 for 20 grams I’d like to know it’s not just repackaged cyanoacrylate glue.
Cross-threaded only one heel several years back, but having removed and installed many, I know how easy it is to do. Nice fix.
I found that using a larger round disc like a washer (or $2 coin in Canada) worked much better to start getting it threaded straight and then use a large slot screw driver. It seems to apply a more even pressure across the cap.
ya use a loonie or a toonie eh?
BTW did you hear the gov are discontinuing the loonie cuz the newfies are breaking their teeth tryin to get the chocolate out
Lou, didn’t you make a tool for threading that cap back on that engaged the entire length of the slot? I cant seem to find the post but was hoping to recreate it. THANKS!
I made a tool from a gasket scraper, shaped and hollow ground, but a “windage bit” seems to be a commercially available option, see this post:
https://www.wildsnow.com/22876/tech-binding-toolset-part-1-screwdrivers/
And here is the DIY post:
https://www.wildsnow.com/8560/custom-tool-for-dynafit-plum-atk-more/
Lou
Thanks for the links! I could not find a suitable sacrificial scraper at the hardware store so I ended up cutting down the tip of a large flat head screwdriver at a point where the shank was the correct thickness to fit tightly into the slot on the DIN adjust. I had to use a cut off wheel as the steel was too hard for a hacksaw. I then squared the tip as best as possible, heavily deburred the whole thing and wrote “DYNAFIT” on it just because…..It worked just fine and did not cam out or damage the aluminum barrel. As far as the rest of the post if you remove the thimble bushing that cradles the double spring you can use a regular thru hole tap on the housing which I found easier to get centered in the threads. I lubed the threads with alcohol during tapping and incrementally increased the tapping depth while backing the heel off a bit each time to clear chips. After that I dialed out the vertical release din, greased everything and reinstalled the housing to the ski. Very painless with the correct tools! THANKS!