I had replaced the O2 sensors and reinstalled the catalytic converters and I was tightening the bolts onto studs for catalytic converter. JTIS says 60-80 NM and the stud sheared at less than 70.
Take it off now and remove broken stud.

 

I usually break at least one stud when removing the cataverters (gearbox out etc.) and I keep a half a dozen in stock just because.

The stud will usually break above the unthreaded section so enough to grip with pliers AFTER you heat the mount ear 'cherry-red' with a torch.

Never had to drill one and have replaced a few dozen over the past several decades.

They are NOT common steel studs, The nuts are some sort of corrosion resistant alloy as well.(inconel?)

Dealer has them, I just bought some a few weeks ago because I was running low.

 

Thanks. I got it out and will get a new one. I have some yellow zinc studs but they are a little shorter.

 

What torque do you suggest? thanks

 

I just 'double-nut' them and snug them in. I use Nickel High-Temp Anti-Seize upon installation. (on everything exhaust related)

When you use the OEM special nuts (locking-type) they will be tight to thread and will torque the studs anyway.

bob

 

So just good old snug tight, maybe 40 nm on the nuts?

 

I never measured the torque, I just snug to tight like any common M8 fastener. (probably closer to 25nm)

 

I am going to replace them all, and not torque to what JTIS says.
They come out easy with my stud remover.

 

It’s not the Nm torque that is the issue, it’s the operating temperature.

As someone who used to track race, it’s the high temperatures that seems to weld stuff together. We used to use high temp lube (lithium/copper) etc on the contact surfaces/threads etc that aided in quick release like wheels and brakes.

However be aware of any safety critical equipment like wheel lug nuts. The factory Nm Spec isn’t the same using lube. You need to have a “feel” for things. Check after a hard ride.... and later check again... and the later again.