How do you remove heli-coil insert?

matt194

Petty Officer 2nd Class
Joined
Oct 30, 2007
Messages
124
I installed a heli-coil on the block of my 79 rude and the heli-coil insert wasn't as long as the threads. So I decided to put another insert in the hole and now I don't know how to get it out. Can I just break off the tab that is used to screw in the heli-coil insert and use the two inserts as one? Or should I remove the second heli-coil insert I put in the hole?
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: How do you remove heli-coil insert?

So, you now have two of them in the hole? That will work if you break off the tabs and the total length is correct. Otherwise, are they blind holes or can you simply screw them right on through?

About the only way to remove one from the outside is bend the outer end inward, forming a sort of crude tab to grab with needle nose pliers and unscrew it out.
 

matt194

Petty Officer 2nd Class
Joined
Oct 30, 2007
Messages
124
Re: How do you remove heli-coil insert?

Yes, I now have 2 in the hole and the total length of the two is the correct size for the hole. How do I break off the tab?
 

iwombat

Captain
Joined
Jul 12, 2006
Messages
3,767
Re: How do you remove heli-coil insert?

You could also spin them out with a left-handed drill bit.
 

dodgeramsst2003

Petty Officer 2nd Class
Joined
Apr 15, 2008
Messages
177
Re: How do you remove heli-coil insert?

If you have two stacked together in the hole, its only going to work if they are aligned perfectly. I realize that they are screwed into a tapped hole, but if they didn't mate quite right, you might have problems. Otherwise, its like trying to put a bolt in two slightly misaligned bolts. We use them at work all the time, best solution is to get a longer helicoil. Second best solution would be to use one even though its slightly too short.

Chris
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: How do you remove heli-coil insert?

Yes, I now have 2 in the hole and the total length of the two is the correct size for the hole. How do I break off the tab?

You don't say what size they are or where they go. The usual way to break the tab off is give it a tap with a hammer and punch. But if it is going to fall inside the engine or something (like a spark plug hole) then grab the tab with a pair of needle nose pliers and give a yank.

Don't worry about the threads aligning. The tap is constant pitch throughout it's length. Even if there is a gap between the heli-coils, doesn't matter.
 

matt194

Petty Officer 2nd Class
Joined
Oct 30, 2007
Messages
124
Re: How do you remove heli-coil insert?

The heli-coil is in a head bolt hole, so I could just knock the tab out and grab it at the back end of the hole. I had the same thought as dadgeramsst2003, how do you know the two helicoils will be in the right position to allow the screw to go completely through? I can just see breaking the tab and then the bolt not going all the way through and not having anyway to get the heli-coil out.
 

detourkid

Cadet
Joined
May 18, 2008
Messages
19
Re: How do you remove heli-coil insert?

knock it out and just go to next size tap cause heli-coils are an ok fix..
Unless you have no choice then i would only use one heli-coil and just loc-tite it in, I do it at work and it holds
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: How do you remove heli-coil insert?

The heli-coil is in a head bolt hole, so I could just knock the tab out and grab it at the back end of the hole. I had the same thought as dadgeramsst2003, how do you know the two helicoils will be in the right position to allow the screw to go completely through? I can just see breaking the tab and then the bolt not going all the way through and not having anyway to get the heli-coil out.

In the first place the tab won't take the heli coil out--only put it in. In the second place, I said that the thread pitch is constant and there is no "right position" to allow the screw to go completely in. It will align just fine. A thread pitch of 20 TPI (example) advances 20 turns per inch and is constant for the entire length of the hole, no matter how long it is. So your screw advances 20 turns per inch and when it catches up with the second heli-coil it will be just right because it also advanced 20 turns per inch as it went in. Believe it or don't believe it.
 

matt194

Petty Officer 2nd Class
Joined
Oct 30, 2007
Messages
124
Re: How do you remove heli-coil insert?

FR was correct. I knocked out that tab and the bolt went all the way through with ease. Sorry for doubting you I just didn't want to run into anymore problems. Anyway thanks for all the help.
 
Top