VC fluid quantity help?

[KarlT]

I hear you, it seems a very delicate business. Although a de-coupler would be a huge bonus as you learn how tight, or not, your DIY refill is.

[alewing]

Hi,
I like this subject and I am considering some experimentation myself, moreover I could have the ability to construct a test rig. I too have the fluid (Wacker Silicone 100,000AK), but as yet have not purchased the seals (any help with these would be great). My VC works fine at the moment, but it has done roughly 150k miles.

From the research I have done the percentage of air to be left in seems to be 14-16% (or 84-86% fluid). So once you have calculated the volume of the chamber and deducted the volume of the plates you will be left with the volume of the space left, you then need to calculate the volume of fluid required to leave said percentage of air and then transpose this into its mass (knowing the density of the fluid). I will try and find some time to put this all into a spreadsheet.

It appears that during construction, the technician will have added/removed fluid (through the plug holes), whilst on the test equipment, to achieve the desired outcome.

I attach some reference links and I have contacted the authors for any further updates. Apologies if you have already seen these links.

http://www.vanagon.com/syncros/technica ... /index.htm
http://shufti.wordpress.com/category/syncro/page/2/
http://shufti.files.wordpress.com/2010/ ... s-engl.pdf
http://shufti.files.wordpress.com/2009/12/vc.pdf
http://autos.groups.yahoo.com/group/Syncro/message/5133
http://www.2wd-goes-syncro.de/

So, not only is the required air volume inconclusive; but so is the argument regarding the 'microscopic' burrs left on the plate after the 'holes' and 'slots' have been punched out; potentially meaning that worn/used plates will still be ineffective with new fluid (of the correct volume)
More work required me thinks!!

Looking forward to any updates and i'll keep you posted on any more of my findings.

Good luck!

[stevealex]

https://club8090.co.uk/forum/viewtopic.php?t=66501" onclick="window.open(this.href);return false;

This thread has lots of debate about this subject. I think the conclusion of this thread, is that there is so much misinformation about refilling a vc yourself it will require a lot trial and error. With each trial being a removal of the front diff,I would rather get an exchange unit.

I think of vc's as a clutch and although I'm more than happy to change a clutch plate, I wouldn't consider relining one.

Steve

[alewing]

Reply from Derek Drew... maybe not the most informative or conclusive, but has some interesting links....

Lets see..... updates...... air percentage maybe try 8%.

Fluid viscocity try 30,000.

Adjust these two via testing after your first assembly.

See also http://www.sethdrew.com" onclick="window.open(this.href);return false; and http://users.rcn.com/derekdrew/vanagon/ ... syncro.htm" onclick="window.open(this.href);return false;

[IdahoDoug]

Alewing,

Keep researching - the 14% range is way too much air. The source of that has publicly corrected himself - it was an original thought a looooong time ago.

A plea not to turn this thread into another discussion of what people THINK the refill should consist of. It's an exacting scientific process and I am hoping simply to have the gods throw a little sunshine my way. Ooh, noticed I have a message!

Doug

[IdahoDoug]

Crud - false alarm on the message.