Broken screw thread.

[MarcinPor]

Hi Guys. I was instaling skid plate today and I have messed up thread. Is there any way to repair it ?

 

[MarcinPor]

 

[MarcinPor]

Hi Guys. I was instaling skid plate today and I have messed up thread. Is there any way to repair it ?

 

[gv550]

Use a helicoil kit, includes a tap and coil of metal thread to wind in with the included tool. Be careful to not drill any deeper than the original hole.

 

[MarcinPor]

Use a helicoil kit, includes a tap drill and coil of metal thread to wind in with the included tool. Be careful to not drill any deeper than the original hole.

I never did that before and I would rather someone else do it. Someone who deal with stuff like that on daily bases. Who should I look for ? Regular mechanic ?

 

[gv550]

Lots of expertise right here on this forum, where are you? Someone local may chime in and offer help, just bring beer.
Most experienced mechanics or machinists will have done this repair numerous times.

 

[MarcinPor]

Lots of expertise right here on this forum, where are you? Someone local may chime in and offer help, just bring beer.
Most experienced mechanics or machinists will have done this repair numerous times.

I'm in Lake Forest, CA I could try but I really don't want mess it up

 

[MarcinPor]

Lots of expertise right here on this forum, where are you? Someone local may chime in and offer help, just bring beer.
Most experienced mechanics or machinists will have done this repair numerous times.

Thanks Brother I will try find someone that can do it right

 

[holligl]

Thanks Brother I will try find someone that can do it right

The other thing would be to try it yourself on a piece of scap metal first to get a feel for it.

Sent from my SM-N950U using Tapatalk

 

[EricV]

I'm in Lake Forest, CA I could try but I really don't want mess it up

It's not all that hard. But that said, I'm a machinist and have done more than I can count.

The main thing here is you have a blind hole, so if you thread the helicoil insert all the way in it's difficult to break the installation tab off at the 'bottom' of the hole.

Biggest issue doing the job is starting the tap strait so you have nice threads to the bottom of the hole. Some kits have bottom taps, but IIRC, most come with a taper tap which is easier to start, but does not allow threads to the bottom of a blind hole.

Give us another pic backed off a bit. Is that one of the engine mount holes above the pipes?

 

[Xclimation]

It's not all that hard. But that said, I'm a machinist and have done more than I can count.

The main thing here is you have a blind hole, so if you thread the helicoil insert all the way in it's difficult to break the installation tab off at the 'bottom' of the hole.

Biggest issue doing the job is starting the tap strait so you have nice threads to the bottom of the hole. Some kits have bottom taps, but IIRC, most come with a taper tap which is easier to start, but does not allow threads to the bottom of a blind hole.

Give us another pic backed off a bit. Is that one of the engine mount holes above the pipes?

Can he just tap it using the same size tap and thread pitch? Then if that doesn't work, go up a size? I'm deferring to your experience and wanting to know myself for future reference. Thank You in Advance!

 

[MarcinPor]

It's not all that hard. But that said, I'm a machinist and have done more than I can count.

The main thing here is you have a blind hole, so if you thread the helicoil insert all the way in it's difficult to break the installation tab off at the 'bottom' of the hole.

Biggest issue doing the job is starting the tap strait so you have nice threads to the bottom of the hole. Some kits have bottom taps, but IIRC, most come with a taper tap which is easier to start, but does not allow threads to the bottom of a blind hole.

Give us another pic backed off a bit. Is that one of the engine mount holes above the pipes?

Yes. It is above pipes. I believe that is M10 1.25 I will try find someone it's new bike if I mess up it would be very painful.

 

[MarcinPor]

It's not all that hard. But that said, I'm a machinist and have done more than I can count.

The main thing here is you have a blind hole, so if you thread the helicoil insert all the way in it's difficult to break the installation tab off at the 'bottom' of the hole.

Biggest issue doing the job is starting the tap strait so you have nice threads to the bottom of the hole. Some kits have bottom taps, but IIRC, most come with a taper tap which is easier to start, but does not allow threads to the bottom of a blind hole.

Give us another pic backed off a bit. Is that one of the engine mount holes above the pipes?

 

[MarcinPor]

It's not all that hard. But that said, I'm a machinist and have done more than I can count.

The main thing here is you have a blind hole, so if you thread the helicoil insert all the way in it's difficult to break the installation tab off at the 'bottom' of the hole.

Biggest issue doing the job is starting the tap strait so you have nice threads to the bottom of the hole. Some kits have bottom taps, but IIRC, most come with a taper tap which is easier to start, but does not allow threads to the bottom of a blind hole.

Give us another pic backed off a bit. Is that one of the engine mount holes above the pipes?

 

[MarcinPor]

 

[ballisticexchris]

Just grab a tap and cut the end off and carefully file the ends. Making it a bottom tap. Re-tap the hole.

 

[EricV]

Can he just tap it using the same size tap and thread pitch? Then if that doesn't work, go up a size? I'm deferring to your experience and wanting to know myself for future reference. Thank You in Advance!

@MarcinPor - Thanks for the additional pics. It's where I thought. Yes, very painful since that's the engine block. A timesert may be better for this application. Google both Helicoil and Timesert and consider both.

@Xclimation - He's stripped out the original threads, so you CAN use a Helicoil tap, which is a bigger size, to tap new thread to the original size Helicoil insert.

If he tried to tap the original bolt size, there would be no material to tap. The Helicoil and Timesert kits come with a tap the size of the insert, which is larger so the insert has the I.D. of the original threads. That way you can use the original bolt again.

At this point, he likely does not need to drill, since he's stripped the hole out to nearly the size of the drill bit for the insert.

Basically, you will need to determine the correct size and pitch of the original bolt, purchase a thread repair kit of either Helicoil or Timesert and follow the directions of said kit.

This usually means drilling the existing hole large enough to tap for the insert. (hole may already be large enough), then tapping the hole for the larger insert threads. If you tap strait, you have a much greater chance of success.

Now insert the insert with the provided installation tool. Generally with Timeserts, you use a thread locking compound. With Helicoils you don't. Again, follow included directions.

With a Helicoil insert there is a break away tab at the bottom that the insertion tool uses to twist the tab into the new threads. This, ideally, should be broken off and removed before threading the bolt back in.

I forget if Timesert has a similar piece.

 

[cycledelic relic]

Mine was stripped jus the same.... 12mm bolt.... Mabe 1.5 thread
A good friend owns a machine/welding shop near my home & did the repair with a Timesert. Less than $100
We removed the front wheel to get more room for drilling the hole straight on.
He much prefers Timeserts over Helicoils due to problems when breaking install tab. Timeserts expand when in place I think.
Everything came out jus fine. I even got a $388 refund from the dealer who supposedly changed the oil & filter before my purchase....or didnt....but thats a different story

Sent from my LML212VL using Tapatalk

 

[EricV]

Just grab a tap and cut the end off and carefully file the ends. Making it a bottom tap. Re-tap the hole.

Yes and no. Taps are hard enough that you're not going to file anything off. You need to grind it off. But it's important to tap as far as you can before you grind down the tip to get more thread.

Point of fact, a taper tap, which has a tapered point to aid in starting the tap, pushes the cut bits forward. A true bottom tap pulls the cut bits back out of the hole by design.

I have a 12mm by 1.25 Helicoil kit on hand that I don't need.

 

[ballisticexchris]

Generally with Timeserts, you use a thread locking compound. With Helicoils you don't. Again, follow included directions.

With a Helicoil insert there is a break away tab at the bottom that the insertion tool uses to twist the tab into the new threads. This, ideally, should be broken off and removed before threading the bolt back in.

I forget if Timesert has a similar piece.

You can either snip off the tang before inserting or use a Tangless Helicoil for repair. I personally use red 272 Loctite for both Helicoils and Timeserts (if the repair is permanent). With the Helicoil I use the 272 sparingly and let it cure completely. I then use a dental pick to clean out the excess before inserting bolt.

Yes and no. Taps are hard enough that you're not going to file anything off. You need to grind it off. But it's important to tap as far as you can before you grind down the tip to get more thread.

Point of fact, a taper tap, which has a tapered point to aid in starting the tap, pushes the cut bits forward. A true bottom tap pulls the cut bits back out of the hole by design.

I have a 12mm by 1.25 Helicoil kit on hand that I don't need.

I have made a bunch of bottom taps by cutting the ends off and using sharp edged files to clean up the ends. And I simply tap a little and back out to blow out the shavings. Looking at the pictures It looks like it was just cross threaded a bit. Time serts are stronger but a lot of material has to be removed to fit.