Vanagon EuroVan
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (July 1999, week 3)Back to main VANAGON pageJoin or leave VANAGON (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Tue, 20 Jul 1999 10:09:49 -0700
Reply-To:     sxs@CONCENTRIC.NET
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Steve Schwenk <sxs@CONCENTRIC.NET>
Subject:      Re: Viscous Coupling Expert Located & Interviewed
Comments: To: Derek Drew <drew@INTERPORT.NET>
Content-Type: text/plain; charset=us-ascii

Thanks, Derek...i was days away from sending my VC to Wheddle. I will stand by until this develops a little more. Does your source do rebuilds??? I want my 4wd back! Yes, you get the VC award! steve

Derek Drew wrote: > > I located this morning an expert who works at a manufacturer of viscous > couplings. As part of a lengthy interview, he said these things: > > 1. The viscous coupling fluid goes bad over time when it acquires small > metal particles from the surrounding metal and suspends these particles. > > 2. The process of having the fluid go bad is called "gellation" and was > caused as a reaction causes a gas to be formed. > > 3. You can fix a VC by replacing the fluid with fresh fluid. You should > also examine the condition of the plates. > > 4. The percentage of air in the viscous couling is critical, and the > percentage is almost always a low of 80% and a high of 86%. He said that if > you went above an 86% fill then you would have the VC activating on the > highway during normal driving and a dangerous situation would exist. If you > went below 80%, he said you might never achieve lockup, even when stuck. He > said all these numbers are subject to investigation and confirmation, which > he will try to give me in August after consulting with Europe to check on > our exact unit. He said the probable range for our vehicles is 84% to 86% > air--possibly closer to 86% for a vehicle intended to go off road as ours is. > > 5. He said a room temperature VC should *not* be under any internal > pressure, and that it might be a simple fix to partly repair a VC to simply > open up the bleeder holes and let the fluid under pressure in there out and > then put the plugs back in and keep using the unit. > > 6. He said that he wanted to help us in order to keep VCs from getting a > bad rap amoung OEM manufacturers. He said that even if his company did not > make the SDP units themselves, his company would have an interest in > helping us and making sure our VCs were not wearing out prematurely and > that they were being rebuilt properly. > > 7. He said that if Wheedle and Oregon Transaxle were refilling the VCs > without letting any air get into them (which both Wheedle and Oregon told > me!!!) then the rebuilds from Wheedle and Oregon would be faulty. The > symptoms would be early wear, intense heating of the VCs, and lots of > premature lockup. > > 8. I observed that this might be the reason Wheedle and Oregon both told me > they are moving to a lighter formula fluid--that they are mistakenly not > adding the required 14% air and that they are not rebuilding the units > correctly. The GKN official agreed that this is a logical possibility. He > said the idea of a VC being 100% filled with fluid was something that would > simply never be done under any circumstances. This statement tracks the > statements of the engineer Wolfgang in Tim Smith's article from VW in 1979. > > 9. I believe it is possible that after my guy checks with SDP that someone > will shut him up and they won't talk to us any more. > > 10. He said the proper refilling procedure is to apply pressure at one > little hole while applying a vacume at the other little hole . > > 11. He said the key to preventing the fluid going bad over time was > additives in the fluid that his company routinely uses. He said it is > possible that SDP does not use these additives. > > 12. He said the fluid gets hot and that this is what causes the lockup. > > 13. I asked him why the VC doesn't appear to have any air in it and asked > him why it seemed to be 100% fluid. I asked if perhaps this was a special > VC that required 100% fluid. He said that no, this would not be the case. > He said that in manufacturing the air is added and then the air gets mixed > up in the fluid and occupies the little holes between the plates of the VC > and you cannot see the air any more. > > 14. He said not to quote him on any of this. I guess that means I should > leave his name out. :-) I think what he really meant was that he wanted to > investigate and confirm what he told me. > > CONCLUSIONS: > > a) Anyone with a bad VC should hault any work being done by Wheedle and/or > Oregon until we resolve the issue of the % air. > > b) Anyone with a bad VC might want to simply vent it, reseal it, and reuse > it, and see if that fixes the problem. > > c) Derek gets this week's "VC Award." > > At 11:13 PM 7/19/99 -0700, you wrote: > > > >Derek, > > > >at the risk of stating the "bleeding obvious", for the fluid to under > >pressure there must be some "airspace" in the VC. Wasn't there some > >discussion about whether the VC was completely filled with fluid or not? > > > >Alistair > > > > > > _______________________________________________ > Derek Drew New York, NY > CEO, ConsumerSearch > drew@interport.net > > 212-580-6486 > 917-848-6425 (cell; this phone is a reliable way to reach me fast or to > leave messages) > > Alternate numbers for the industrious phone caller that wants to try every > avenue: 202-966-7907 (Work), 212-580-4459 (Home), 202-966-0938 (Home)


Back to: Top of message | Previous page | Main VANAGON page

Please note - During the past 17 years of operation, several gigabytes of Vanagon mail messages have been archived. Searching the entire collection will take up to five minutes to complete. Please be patient!


Return to the archives @ gerry.vanagon.com


The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.

Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.