VC fluid quantity help?

[IdahoDoug]

For 2 years I have worked to save a Syncro here in the US. I have personally done everything on it small and large and took it from a deteriorating refugee to a durable beast back at her former glory in my own garage and with my own hands. The last remaining obstacle is the viscous coupling. I diligently researched it a while ago, started discussions about it, made phone calls, etc as I knew that a few months hence (this month) the vehicle would be fully ready and I wanted to be ready tackle the VC. Assistance arrived in the form of SyncroSimon who contacted me offline months back, and offered to provide the correct fill quantity by weight. He needed the weight of my empty VC plates and had access to a corresponding paper with the associated fill weight.

Now, I have learned he has left the Syncro community and I seem to be at a dead end as to the correct silicone fluid quantity. Could someone please take pity on me and help me figure this fill out? I have a gallon of the correct fluid, and the seals. I am servicing the transmission and while it is out I would like to take the VC out and refill it.

Please? Pretty please? Offline or PM is fine - I understand and respect the nature of this information.

Thanks in advance,

DougM

[xriss]

hi doug is your vc working correctly ...is there something wrong with it?...cheers chris

[xriss]

is there anything wrong with your vc doug? if so could you describe...cheers chris

[IdahoDoug]

It's just weak. No binding, no untoward noises. The previous owner only drove it on roads. I am an avid offroader and this vehicle is going immediately into some very remote places in North Idaho and British Columbia where the 4wd system will be vitally needed. We have been offroading our LandCruiser since 1992 and enjoy solo backcountry travel. One of the reasons we moved here. I am also planning to attend an event here called MogFest which is a group of European 4wd machines such as Volvo 303, Unimogs, Landys, and Pinzgaurs in an obstacle course setting. I hope to be able to show the Syncro's abilities there.

I will not be adding a decoupler and shaft as we will be using it year-round and have severe winters where I think the "always on" aspect of Syncro will work well. I fully insulated the entire body and fashioned window insulation panels as well for winter camping. I also am a member of our backcountry Search and Rescue team and will need the system at full effectiveness for those missions.

So, hope I've explained my intentions well enough. As a matter of principle, I am also very determined to do everything on this vehicle personally as I will act as sole mechanic for it when out in remote country where a tow is simply out of the question.

Thanks!

[xriss]

all here doug,ut with out the test equipment you might end up with a worse performing vc than you started with https://club8090.co.uk/forum/viewtopic.p ... yncrosimon" onclick="window.open(this.href);return false;

[toomanytoys]

Well.. I could have bought a new vc, but as it happened a decoupler came up in a deal over other stuff 2.5 years ago.. I have a slitghtly stiff VC, its been like it for 6 years, hasnt got worse but then I have been dropping the prop for all long runs (apart from 1 winter run a couple of years ago), I just never got round to fitting the decoupler..
The tight VC works so well off road that I also didnt want to change it....
The decoupler is fitted now, so I have the best of both worlds.. no strain on the driveline in summer on runs, 4wd if its needed, can run 4wd when the conditions are slippy, and good offroad performance..

Yes of course a new VC but that would have cost me more than what was part of the deal.. I'd still be dropping and fitting the prop if I hadnt got it.. and I am pretty swift at that now...

[IdahoDoug]

Yes, I've read that thread more than twice in preparation for draining and refilling my VC, but it doesn't get close to enabling one to determine fill quantity. Just peters out with some foreshadowing of an information release that didn't seem to happen. I can handle the scale, precise weighing, clean and mark each component properly, install my new seals, and pour in my fresh silicone. Just need to know how much air to leave in, by knowing the chart is available such that when I pull the unit apart and weigh the plates, someone will be able to tell me to refill with 278g. Or 286g. Etc.I've already done 10 repeat timed/torque tests with the existing VC. I have another VC in the garage I'll also get a number for and can then provide you folks with 3 data points and fill weights and plate weights. Get a few of us shadetree mechanics out doing this and suddenly enough dots on a central chart become an effective tool for others who cannot afford a new VC but would like to keep their girl out on the trails. Thanks!!

[KarlT]

Yeah, shame S'Simon leaving, he was always ready to look/try new things & willing to share & documents his experiences.
Can't help you with the refill info, but we do need before & after pics of the resto.

[stevealex]

Hi

I remember seeing a thread on IG syncro 16,the german forum (i think I found a link to it on here?), where they were refilling vc's at a forum meet. They appeared to have the figures and I think one of them was recently offering this as a service on ebay. If you can translate a post for that forum you might get somewhere. People do seem to be very wary of servicing the vc's themselves, but ultimately you are able to go through the same processes as professionals refurbishing them. I think that they will probably have much more accurate equipement than we all do at home - which I fear may be the bugbear in all this.

Good luck
Steve

[hugomonkey]

http://www.ig-syncro16.de/wiki/Viscokup ... andsetzung" onclick="window.open(this.href);return false;
here you go

[IdahoDoug]

Jason et al,

Thanks for the link. My wife speaks German and I've been through that site also. They seem to think that a 280g fill is the number, but I think there's ample evidence that the VCs have slight internal volume differences from the plates that have to be accounted for. The fill needs to be very precise as to volume, so the "one size fits all" approach they used is something I'd only do if I had a decoupler so the VC's only operating when I'm offroad. I'm a former Worldwide Powertrain Planner for GM and the fill quantity shapes the VC's function. So, was hoping someone would steer me to someone I can provide my plate weights to for a better "guesstimate" on my fill so I can confidently be out in remote areas knowing that even if I'm well and truly stuck and spinning wheels and giving her the boot, I won't have a weak VC.

I've noted many references to a factory fill chart listing plate weights in one column and fill weight in the other column. I am hoping that has not been lost to history, as the VC is, in many ways, the heart of the beloved Syncro we gather here to discuss and enjoy.

DougM

[syncropaddy]

Yeah, shame S'Simon leaving .....

Yeah ... I miss winding him up !

[KarlT]

But I thought he had a de-coupler?

[syncropaddy]

But I thought he had a de-coupler?

Did he? I dunno

[Macflai]

Every time you guys speak about quantities to fill the VC up, I feel scared... I think the discs also should be checked, and you should test the VC, before installing back, in a special tester...

Sorry for being so pessimist but when I visited Mr Walter Hurlimann 6 years ago I was scared while he was screaming at me "IMPOSSIBLE TO CHANGE ONLY OIL, IMPOSSIBLE IMPOSSIBLE!!" and I am talking serious, his son is my witness, he was also there... I left the workshop "having a complex"... and scared... since then never wanted to hear anything about VC's...

I have nightmares about broken gearboxes every night!