Heli Coil & other thread repair options.

[Sako85 Member Find all posts View Profile Close Sako85]

I personally would weld the hole up and re-drill/tap it. But also drilling it out and tapping to M10 would be ok I would guess, as someone else mentioned its only 1mm each side bigger.

As for Nutserts/Rivnuts... I have a good english made set & I don't think it would work in this instance. The area that holds the nut in place is only designed to me mounted to sheet metal. There maybe 5-7mm of area there that does the 'riveting' and holds the nut in place by flaring out and pulling itself hard against the head on the other side (sheet metal between). In this case the nutsert has to go through the chassis (approx 2mm?), through the old stripped nut(5-7mm?), then poke its head out the other side. Not really anything for the nutsert there to bite into. I think it would grab, just by making a slight donut inside the nut and stay there but would pull out either whilst tightening, or not long after.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

You can get rivnuts that suit thicker material, some of mine are 5 - 7mm and there are others for thicker materials but I agree drilling and tapping is the simplest solution.

Jasen that metal bog stuff works well in some situations but I wouldn't be trying to tap a thread in it. We had a damaged fan shaft (lots of tons of fan and shaft) and it was something like 6 months delivery for a replacement. We used Belzona or one of the equivalents and built up the shaft and sanded it back to size. Lasted well beyond the time needed. Originally it was destined to be changed the minute the new shaft arrived so it was shut down and inspected (I should add lots of monitoring on the oil system for any debris that could be the repair falling apart). In the end it went for 3 years to the next scheduled shutdown.

[mackayvx Advanced Member Find all posts View Profile Close mackayvx]

Actually as a toolmaker you could go M9!.

LMFAO... Tehehe M9. Yes I could if I had a lathe but I've been out of the game for 10 years... Easier money to be made elsewhere.

I will however drill and tap it - I have the tools to do that still!

I personally would weld the hole up and re-drill/tap it.

As for Nutserts/Rivnuts... The area that holds the nut in place is only designed to me mounted to sheet metal. There maybe 5-7mm of area there that does the 'riveting' and holds the nut in place by flaring out and pulling itself hard against the head on the other side (sheet metal between). In this case the nutsert has to go through the chassis (approx 2mm?), through the old stripped nut(5-7mm?), then poke its head out the other side. Not really anything for the nutsert there to bite into. I think it would grab, just by making a slight donut inside the nut and stay there but would pull out either whilst tightening, or not long after.

I was hoping the M8 rivnut would have an outer diameter of of about 13mm, drilling for that would just about eliminate the nut in the chassis.

You can get rivnuts that suit thicker material, some of mine are 5 - 7mm and there are others for thicker materials

Mj - is there any chance you could measure the outer diameter & thread depth of an M8 & also a M10 rivnut for me please?

If the drill for the 8mm rivnut doesn't clean the welded nut out, maybe the drill to suit a 10mm will.
That being the case I will rivnut the whole lot M10 and modify the bashplates to suit.


I like the idea of going to M10 for those bash plates as they are pretty heavy.

Thanks dudes.

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

An M8 Rivnut is 10.5mm diam, my kit doesn't go to M10 but you could safely assume it would be at least 12.5mm or 1/2 inch.

Cheers Andrew

[mackayvx Advanced Member Find all posts View Profile Close mackayvx]

An M8 Rivnut is 10.5mm diam, my kit doesn't go to M10 but you could safely assume it would be at least 12.5mm or 1/2 inch.

Cheers Andrew

Ahh OK thanks for that AJ. They have thinner walls than I expected.

At least if I tap the hole M10, I can still have the option of a M8 rivnut if it all goes bad.

[Guest Close Guest]

Which cross member has the affected nut?

If you changed them all to M10, the bolt head won't fit into the bolt head protector.

[mackayvx Advanced Member Find all posts View Profile Close mackayvx]

Which cross member has the affected nut?

If you changed them all to M10, the bolt head won't fit into the bolt head protector.

Yes Andrew, it is the center cross member. The one that has the bolt head alloy protectors...

The thing is, those bolt head protectors are gone, the are somewhere on the Verila Point road, up on the cape.
The corrugations were that bad that I lost those two bolts and the alloy things.
The front bash plate was making a hell of a banging sound and it was lucky I had spare bolts and loctite.

So since then I've been running it with panel washers / spring washers / loctite combo.
And its been all good.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Don't have M10 rivnuts either. Would take some fancy language and a big tool to set those suckers!