'Helicoil'

[Cha7z]

I have 1 hole in the gearbox sump of my Rover V8 that the thread is US. To get someone in to helicoil it is expensive so I'm thinking of buying a set and doing it myself.
Any suggestions or things to look out for when I'm doing it? I guess I can only get it wrong so many times before I can't make the hole any bigger for the helicoil!!!
Thanks!

 

[rtbcomp]

Make sure the hole is deep enough to take the Helicoil.

Use the correct drill (it should come with the set) and make sure you don't drill the new hole cock-eyed, it's quite easy to do - don't ask!

There are Helicoil look-alikes which may be cheaper, but I can't for the life in me remember what they're called.

 

[Cha7z]

Make sure the hole is deep enough to take the Helicoil.

Use the correct drill (it should come with the set) and make sure you don't drill the new hole cock-eyed, it's quite easy to do - don't ask!

There are Helicoil look-alikes which may be cheaper, but I can't for the life in me remember what they're called.

Thankyou!! I wont ask, but that is my biggest fear! I have to lay on my back under the car. i might be able to use a normal drill but may have to put the right angle attachment on it. that will make it even harder to be sure it is not cock-eyed.....or, as we say in Suffolk 'on the huh'.

 

[piman]

Hello Cha7z,

the ones I use are called Recoil, the largest I have used is 3\8" UNF and in aluminium I find that the tap will go into the hole without needing to drill it out.
However I would assume your sump drain will be about twice that size, so drilling may be necessary?

Alec

 

[Cha7z]

Hi Alec, no, it's not the sump drain, it's one of the sump retaining bolts and it's only 5/16 so I'll give it a try without drilling.....that would save me some worry!!!
Cheers

 

[gordon stephenson]

Is there any reason that you can't just tap the stripped hole the next size up, In your case probably 3/8". If you needed or wanted to retain the same size hex head you could easily make a stepped 3/8" to 5/16"stud.less expense than having to buy a helicoil set,

 

[piman]

Hello Gordon,

the recoil sets are not expensive and saves having a bastard bolt in the set. They are useful to have in case of any future mishap as well.

Alec

 

[Cha7z]

Is there any reason that you can't just tap the stripped hole the next size up, In your case probably 3/8". If you needed or wanted to retain the same size hex head you could easily make a stepped 3/8" to 5/16"stud.less expense than having to buy a helicoil set,

Hi and thanks for the input. No real reason I guess, except that I didn't think of it!! There is room, so no need to retain the original size head (apart from taking 2 sockets under if I ever have to remove it again!!!!). the only priority really is to make sure it does up tight and doesn't leak....like it does right now!

 

[rtbcomp]

Hello Cha7z,

the ones I use are called Recoil, .......
Alec

Them's 'em

 

[gordon stephenson]

I would say that with a 3/8" thread in your casing and a 5/16" nut on the stud the holding force will exceed that of the other tap bolts.

 

[Robotstar5]

Time Sert from Wurth had a good revue in one of the Land Rover mags recently.

 

[gavuk]

I'm with Gordon on this one ....i would install a stud ,,,will help in alignment and wear becomes steel to steel ,,,,nut to stud ,,,,,rather than steel bolt to alloy tapped hole......are you familiar and confident in tapping?....either method requires a hole tapped which is not cocked ...

 

[piman]

Hello Gavuk,

I don't get your points.

Steel on steel is what a helicoil gives and the point about confidence in tapping, both methods require tapping so what's the difference.
I've done dozens of these recoil jobs and in my opinion is the best solution. Keeps every thing standard and gives a stronger than original thread.

Alec

 

[gavuk]

helicoil does indeed give steel to steel contact ,but is more likely to catch and snag (in my experience) than a nut on a fixed stud , i've replaced dozens of recoils or helicoils ,through holes ,,,i've seen them screw half way out the hole ,or badly installed with the insert standing proud of the hole...
.I don't know how familiar the OP is with tapping as he is relatively new here ,so as both methods require tapping ,he needs to be confident in tapping it square /not cocked .....for both methods helicoil or stepping up a size is all i was trying to point out ....didn't suggest there was a difference! both require care to get right ....As Cha7z has already said, he may need a right angled drill to open out the hole ,he needs to know that in the same space he has to use a tap wrench and maybe an insert tool(if he helicoils)
I'd go up a size ,drill deeper or drill through personally ,rather than helicoil,but a stud becomes useful for alignment as well ,which may be of benefit ...we may not agree but hopefully this makes more sense....

 

[rtbcomp]

If you're putting a Helicoil into ally it gives stainless steel to ally contact, which is worse than mild steel to ally.

 

[Cha7z]

Certainly a lot of fuel for thought here gentlemen! And this is exactly why I joined the forum so I am grateful for the time taken to respond!

 

[piman]

Hello all,

just to add to this, some quality manufactures helicoil all aluminium tapped holes as a matter of course, to ensure a long life to the tappings.
I think the stainless and aluminium is a problem where mouisture is present, so not likely to be a problem in this application.

Alec

 

[gavuk]

Cha7z.......any of the above methods will work ,some of its down to personnel preference....rotating a steel bolt into aluminium is not great as the aluminium wears and is easily stripped...Corrosion as RTb says can be a problem,as the aluminium corrodes sacrificially to protect the steel,making the bolts seize ..in some materials ,softer or weaker it can be beneficial to use a coarse thread ,ie bsw or unc instead of bsf or unf ,metric may use a coarse pitch as well..m8x1.25 being standard m8x1.5 being coarse ..in reality we are being picky ...so whichever method you find easiest to get parts or access to ,will work,i would also suggest using grease on the threads when bolting up ,copper/alloy slip is my favourite but any grease is better than none.....Good luck with your project

 

[Cha7z]

Thanks again to all of you for your help and input. It is appreciated.

 

[Garreth]

Time Sert from Wurth had a good revue in one of the Land Rover mags recently.

We use these at work - they're awesome !

The insert is a tube rather than a coil - so they're easier to trim to length before or after installation, and they son't tend to wind out like a coil sometimes does.

We also use recoil and v-coil as well - but i prefer the Wurth stuff escpecially on fine threads.

Garreth