Helicoil problem

[Peter Naulls]

Can anyone advise how to deal with a protruding helicoil? Copious amounts of oil started leaking from the camshaft bush retaining bolt and today I found out why. It looks as thought the helicoil insert has wound itself out by a turn or so, though it doesn't seem to be loose. 

Should I dremel the end of the insert? I'm a bit concerned about getting swarf everywhere and access is pretty limited. Also wondering if it will do the same again when I reassemble everything. I don't think there is enough to get hold of and remove it.

   

   

[jpsmit]

I might see if I could bend the protruding bit up enough to get some pliers on it and unwind it completely and get a new helicoil to replace it.

[Chris KC]

I was just thinking the same. It should be possible to get a blade behind that and grab the end with pliers. The danger is whether you may damage the thread in the casting; but I would try this before attempting to cut it. A bit of a long shot but have you tried putting some pressure on the visible end to screw it in deeper? With a warm case the chances would be better. In any case, helicoils are not generally oil-tight and you will need some sort of additional seal. You might do just as well to put a suitably-sized sealing washer over the top of it.

[Howard Wright]

Hi Peter

I would be tempted leave well alone ….but….to braze an oversize washer under the head of a cap head bolt. Making sure that the gap between the washer and bolt stem doesn’t fill with braze. Then use a similar size fibre washer over the protruding Helicoil. Hope this makes sense? 

I always use a fibre washer/ brazed washer under a cap head bolt on the cam bearing retaining bolt. Seems to give a leak free solution!

Cheers

Howard

[jonblob33]

Hi, I have a helicoil removal tool if you are not too far away from South Yorkshire. Will send a picture later today. It works every time. 
Kevin.

["Slack Alice" Simon]

They come out easily if you can unpick enough of the end to grab with long nosed pliers or side cutters.

Then they can be unwound out, they collapse a bit, and so loosen.

Try tapping the hole a bit deeper (you need the tap the correct size) before inserting a new one.

If you don't want to do that, cut the next insert short with a sharp pair of side cutters, de-burr the end with a small file before inserting.

[Colin Cooke]

Hi Peter,

As Chris says, just grabbing the proud bit, will likely cause a bit of damage to the top of the thread. You may get away with it, if you start to wind the helicoil out, as soon as you have a good hold - rather than just pull.
The ideal, is if you can use a sharp punch (or screwdriver) to bend the proud bit across the centre of the hole, and use the original helicoil insertion tool to wind it out. The problem with this is that the block is in the way.
Jonblob is correct; there is an 'official' helicoil removal tool. It is basically a triangle on a stick, with sharp edges that grip on the top ring of the helicoil, and you unwind it out. Again, the block may get in the way, so the standard tool may need the handle modifying.

Hope this helps.
Good luck,
Colin

[squeak]

as Simon has said "use a pair of sidecutters" not as a cutter but end grippers and wind it out.
Colin has described the official tool which suggests that a tapered 3 corner file may suffice, especially if its narrow end is cut off to leave just enough to enter the first few coils.

[David Stepney]

I have successfully extracted a helicoil that has stood proud like Peter's by using a small screwdriver to tease the free end up and then unwind it with a pair of sidecutters to grip it. According to the instructions that came with my kit, one is supposed to wind the insert in until it is one turn recessed into the hole. On the one occasion that I have had to extract it, the tang fell off before I could do this!

[Colin Morgan]

Having done this recently with a sump-bolt hole - IF you can get hold of the end, then try twisting the end around (anti-clockwise) so that the 'spring' tightens smaller allowing the wire to be pulled out of the hole in an ever increasingly longer spiral - or, at least, that is what I found.