Stripped thread, helicoil fix?

[faster]

I see absolutely no reason whatsoever not to helicoil that, but it would need to be done with the proper kit for doing blind holes.

I'd be very surprised it there was already a steel insert in there - there's no good reason to manufacture it like that.

In use there will not be large loads on the threads.

 

[Big Dave laaa]

That will definitely take a heli-coil. The tap required needs a hole just slightly larger diameter than the original threads so plenty of land around the hole. You just need a local engineering shop or similar to sort it for you. We fit heli-coils as standard in aerospace aluminium parts so strength will be better than the original, so no worries there. It's expensive to sort a decent kit so paying someone to do it will be cheapest the option.

 

[gbb]

I keep wavering on this one and it's the lack of knowledge of how much stress or movement goes through a disc caliper to the frame....and if that's a steel Insert thread in OPs photo.
If there's none then a helicoil is a perfectly good option.
If there's the potential for movement as you brake, I'd probably do it anyway but monitor it. In stressy situations I've been known to threadlock the helicoil in position then threadlock the bolt into the helicoil. Lots of pulling on the caliper as you brake might...i say might...cause the same to happen again if you mount a helicoil straight Into alloy.

For real strength there is a steel type insert you can buy, we used them once at work but I can't remember what exactly what they'e called. It's possible this is what's already In OPs photo...

In short...no stress, helicoil . High stress...id think about it more carefully.

 

[Big Dave laaa]

A properly fitted heli-coil will be fine for that application. A steel insert has no advantage over a heli-coil and is used for applications requiring repeated strip downs. The limiting factor is the strength of the aluminium so it is already strong enough.

 

[keithmac]

I prefer Wurth Time-sert over helicoils, gives a more substantial repair especial if you need to remove the bolt in the future.

You need a 4 tool kit to fit them though so best finding somewhere that uses them (garages or engineers).

 

[gbb]

I prefer Wurth Time-sert over helicoils, gives a more substantial repair especial if you need to remove the bolt in the future.

You need a 4 tool kit to fit them though so best finding somewhere that uses them (garages or engineers).

View attachment 405844

They're the ones I mentioned earlier. Much better in many ways.

 

[Big Dave laaa]

Well the Heli-coil is used world wide by every aerospace and defence company for strong reliable threads in aluminium but they are obviously using the wrong system. That Wurth system will leave less material around the hole than a heli-coil but it's up to you. I'll get back to work

 

[davidphilips]

Many good ideas on best way to repair, have a go theres nothing better than the satisfaction of repairing something that seems a real challenge.

If a good repair is not possible then check out ebay never know your luck you may even find an upgrade for reasonable money?

 

[keithmac]

Well the Heli-coil is used world wide by every aerospace and defence company for strong reliable threads in aluminium but they are obviously using the wrong system. That Wurth system will leave less material around the hole than a heli-coil but it's up to you. I'll get back to work

Only going from personal experience (and possibly previously badly fitted helicoils) but I've seen quite a few wind out with the fastener which is why I would choose a Time-sert.

 

[Venod]

The Wurth Time-serts look interesting and something I have never used, I imagine you have to remove more material than required with an helicoil, I have fitted hundreds of helicoils without issue so I am not sure if the extra cost of the Time-serts would be worth it.

 

[keithmac]

6mm insert requires a 7mm tap iirc. You don't drill a massive amount out.

 

[Salty seadog]

It looks as though there might be some thread left further in . I wonder if a longer bolt might be sufficient ?

If the hole is is tapped deeper than where the thread is damaged, would it be possible to use a longer bolt to reach the good thread?

I'd first go with Illaveagos line, would a longer bolt pick up undamaged thread ?

Looking at the photos, it already looks like the thread is like in a steel insert in alloy. That may create a problem when drilling it out. A helicoil kit comes with a specific sized drill and it might not leave enough meat of that insert (If that's what it is) ...or remove it all together. That may be bad as well because the steel insert will be a lot stronger.
I'm rethinking my original post. A steel insert (if thats what it is) is there for a reason, extra strength. Remove it and insert a helicoil ...probably would'nt last, or even be safe.

Well three simplest solution seems to be fine after measuring cadged a longer hex bolt from lbs and have about another 8mm in there, feels like at least half of that is thread as it's holding well.

Thanks all.

 

[gbb]

Well three simplest solution seems to be fine after measuring cadged a longer hex bolt from lbs and have about another 8mm in there, feels like at least half of that is thread as it's holding well.

Thanks all.

This if course brings another point, what a shame the manufacturer didn't use slightly longer bolts in the first place, more thread, more purchase, less likelihood of it stripping in the first place.