Exhaust nut removal

moriniuk · Post by **moriniuk** » 16 Apr 2009 16:49

Has anyone got any "when all else fails" advice for the removal of the castellated exhaust nuts?

I've always managed to get these off previously, but have one at the moment that refuses to move..
I'm using a proper C spanner, soaked the thread in plus gas, applied heat, tried tightening it more before trying to loosen it.
The nut is in reasonable condition, but I'm prepared to sacrifice it.
Maybe the hammer isn't big enough.

Any advice appreciated.

H.

corsaro chris · Post by **corsaro chris** » 16 Apr 2009 18:36

H

Nasty but effective is using a drift in one of the castellations and hitting t'other end. My brother in law did that to tighten up one that was forever coming loose

Good luck!

CC

Post by **morini_tom** » 16 Apr 2009 19:44

yeah sometimes the drift method is the only way. Actually often its the only way on the 501 dart because you actually can't fit a c spanner in!

What I have found in the past is that an allen key (5mm i think) is the perfect size between the flats to fit snugly in the castellation. You can then use the allen key as a lever, which is sometimes more effective than a c spanner if the nut has begun to round off.

Jem · Post by **Jem** » 16 Apr 2009 19:59

NLM sell their own exhaust nut spanner with not just one peg but which fits into half of the castellations. That should give you a really firm grip on the nut.

Is the nut an original or one of these S/S nuts that some people are selling? S/S does not work well with aluminium as it galls & sticks.

Easing oil can take a long time to soak in - days even. It might be worth adding a little extra every day for a week before trying to remove it again. What concerns me is not the sacrifice of the nut but the damage done to the pipes or the thread in the head.

3potjohn · Post by **3potjohn** » 18 Apr 2009 17:22

When you do get something that properly fits some of the slots,try to undo it whilst someone blips the throttle.if the heat and vibrations don't help then when you burn your hands you'll be so mad it will come undone.
Best of luck.

EVguru · Post by **EVguru** » 18 Apr 2009 20:31

A while back I bought a drum braked Sport that had been sitting in a front garden in East Ham for over 15 years. The rear pipe and head were already off, but the front was on and the nut well and truly solid. I did eventually get the nut out with little damage to the thread.

If you're facing a really stuborn nut, then take the head off complete with the pipe. Then you can hold it in a vice and really get some heat into it without the rest of the engine soaking it up. Ideally you need an OxyAcetlene setup. It can take several heating cycles, getting the head really good and hot and trying to get oil to penetrate the threads. If you get a can of freezer spray (Maplin) you can shock cool the nut which will help get it loose.

To turn the nut I made a special tool. I used a bit of 1/4" thick angle iron cut to create two teeth to engague with the nut and made sure it couldn't slip out by using an exhaust clamp.

moriniuk · Post by **moriniuk** » 19 Apr 2009 08:09

Thanks for all the advice.

It's off. Head and pipe are fine, but the nut is well and truly "sacrificed".

I'd tried all the ideas already. In the end it was a little bit more of everything, including enthusiasm, that finally got it to move.

As I was struggling with this ridiculously tight nut I remembered once when I was on the grid for the start of a race and my front exhaust nut had rattled loose. I was frantically trying to screw it back in by hand as my main rival was sitting next to me laughing.
Happy days.

H.

EVguru · Post by **EVguru** » 19 Apr 2009 09:25

I've seen an exhaust nut clamp on a Kanguro and you could easily make your own.

It was really just a pipe clamp with a little tab that engagued in one of the castellations.