John,

You mean something like this:

http://www.vanagonparts.com/temp/nuts.jpg

Exhaust Lock Nut (VW #: 059 129 601)

About $0.25/each

For some reason, very few mechanics seem to use them.

Cheers,

Jeff
www.vanagonparts.com

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
Of John Rodgers
Sent: Wednesday, January 17, 2007 1:59 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Warning! Do not use...

Geza Polony wrote:
> stainless steel bolts on your muffler/catalytic converter.
>
> The more experienced among us know this already. I thought I'd beat the
> corrosion problem by using M8 stainless bolts and nuts for my new Bus
Depot
> cat and muffler. Once they heat up, there's no way to loosen them. I don't
> know what happens to the steel, but it sure isn't any labor saver. The
heads
> just break of when you crank them.  So much for good intentions.
>
>
>
This may not relate, but on airplanes with piston engines, specially
treated steel nuts are sometime used on exhaust studs OR special brass
nuts are used. I think the nuts were more bronze than brass. In my
experience the brass nuts were the nuts of choice, because experience
taught that even the specially treated steel nuts could give trouble.
Anti-seize was not used with brass nuts because they would be subject to
backing off due to vibration. But the friction of the brass on the steel
was sufficient to hold them in place, yet the brass was soft enough that
when it came time to remove them they would turn loose of the stud they
were mounted on. Sometime brass was left on the stud, but the stud would
not be damaged. Far better to discard a brass nut, and clean the stud
threads, than try to replace an exhaust stud - especially with the
cylinder still on the engine and the engine in that airplane. It might
be worth trying them on the WBX unless someone knows a specific reason
why not to.

Regards,

John Rodgers
88 GL Driver