Hi,

I think the blueing, and the straw coloured areas  at the rim of the plates are the result of factory heat treating. I'll take more pics later, showing the un-worn faces (the plates seem to rub in adjacent pairs) which show the colours better. Steel will get that blue oxide at around 300 C, far above normal vc temps :)

I'll also try to get good shots of the holes and see if I can spot the raised edge formed when holes punched (those raised edges have a role in initiating the plate to plate contact during humping)

alistair

On 2011-10-23, at 9:23 PM, neil n wrote:

> Hey Alistair. V cool pics!
> 
> neat insights.
> 
> Is the "blueing" (I use that term incorrectly) in this pic:
> 
> http://shufti.files.wordpress.com/2011/10/img_4918.jpg
> 
> done at the factory during manufacturing or is it due to wear and
> tear?  (I'm thinking the latter)
> 
> Again, nice pics. One can click on them, magnify and see even more detail!
> 
> Neil.
> 
> 
> 
> On Sun, Oct 23, 2011 at 9:00 PM, Alistair Bell <albell@shaw.ca> wrote:
>> Replaced the VC on my syncro today and popped the cover off the old one. I discovered a twisted X-ring, kind of interesting.
>> 
>> http://shufti.wordpress.com/2011/10/23/vanagon-syncro-viscous-coupling-replacement/
>> 
>> 
>> alistair
>> 
> 
> 
> 
> -- 
> Neil n
> 
> 65 kb image Myford Ready For Assembly  http://tinyurl.com/64sx4rp
> 
> '81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/
> 
> Vanagon VAG Gas I4/VR Swap Google Group:
> 
> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines