Rusted and rounded exhaust nut

[Brian_W1]

1. My model of MX-5 is: NC2 2012
2. I’m looking for technical help or recommendations on: rusted and rounded exhaust bolt

Hi everyone, I am trying to install a new back box on my NC. I took one bolt out no problem, but the other one is pretty rusted on and rounded.

I’ve ordered some extractor socket, do you think it will work or should I just go straight to cutting the bolt out?

[MickAP]

Cut it off, your replacement back box (aftermarket) will have to be fixed with nuts/bolts anyway to fix it on.

In my experience get a proper crush gasket if one isn’t supplied with the new box, the thin ones with the holes in aren’t very good at sealing the joint.

[Brian_W1]

Thanks Mick. First time working on any car and am already being thrown in the deep end

What tools do I need to cut? Like a dermal? And where is the best place, in between the gasket?

[Jacob_Rees]

Here’s the type I’ve used. Tap them on with a hammer first then gradually add more torque till it starts to turn. They’ve got me out of a jam numerous times!Nut remover on Amazon

[portvalenil]

I feel and have felt your pain.

Trouble with my flange

My model of MX-5 is: __Sport Black I’m based near: __ I’m looking for technical help or recommendations on: __back box removal. [Screenshot_20221022-150652] [IMG_20221022_150452187] The split nut crumbled under my fingers and was finished off by a screwdriver. If the bolt head is captive then am I right in thinking I have to drive the bolt out backwards or grind it away? What if I drive a chisel in between the two flanges - and is this better done with the rubber hangers off to encourage it…

[Brian_W1]

so the nut is welded on? What kind of evil person would design something like this?!

Time to throw in the towel and give the local shop a call. Thought it would be an easy weekend job

[MickAP]

Yeah cut it between the flanges if room, a thin blade. You’ll probably end up ditching the OEM back box, not many want them SH and they aren’t worth much anyway