A different type of VC failure...

[HarryMann]

http://shufti.wordpress.com/2011/10/23/ ... placement/

[KarlT]

Great pics.
Never looked into what it actually looks like in there, never needed to, but good to have a better idea.
I remember not so long ago the VC was all smoke & mirrors. It seems to be losing some of its mystic.

[ragnarhairybreeks]

yup, my old VC. About the failed seal, I'm not sure if it is a case of bad install at factory and it just took a few years for the compromised seal to leak, or it was excessive pressure pushing seal lip out. Either way seems hard to imagine.

I have new seals, and waiting on some silicone. I'll try rebuild even with those worn plates.

alistair

http://shufti.wordpress.com/" onclick="window.open(this.href);return false;

[HarryMann]

Hi Alistair, they are very worn plates from what I've seen in the past.... be warned.

The seal, well maybe failed in service, they are designed to about 100 bar, that's quite some pressure and if all goes pear shaped long term, might get there, hence the plate damage. Normally the pressure peaks and because it locks properly (humps), drops back immediately before repeating the cycle, thus stabilising.. if it doesn't or can't lock properly, the stabilised cycling - lock/unlock/lock - does not occur and overheating or overpressure or both then can occur.

[lloydy]

yup, my old VC. About the failed seal, I'm not sure if it is a case of bad install at factory and it just took a few years for the compromised seal to leak, or it was excessive pressure pushing seal lip out. Either way seems hard to imagine.

I have new seals, and waiting on some silicone. I'll try rebuild even with those worn plates.

alistair

http://shufti.wordpress.com/" onclick="window.open(this.href);return false;

interesting blog you have there

[HarryMann]

Update: looking at the bearing again, I’m not so sure it overheated. It looks more like corrosion on the outside of the outer race. Still puzzling.

Fretting corosion? They are known to rock in slightly ovalled bearing housing

[ragnarhairybreeks]

Yes, the plates are very worn, worn, and less worn But seeing as the rebuild of the VC is an experiment I'm just going to push ahead with them. Finding new plates over here is kinda hard.

I took some close ups of some of the unworn plates, punched holes - raised edge visible (the "burrs" seemingly responsible for the change in fluid dynamics between plates leading to hump)
large (too large to post here) image - http://shufti.files.wordpress.com/2011/ ... sion-2.jpg

and similar, but lesser, on slots
large (too large to post here) image - http://shufti.files.wordpress.com/2011/12/img_5085.jpg

It was a silly conjecture thinking it was heat discolouration on that inner rear wheel bearing. I'm now leaning towards seal failure and water ingress. Lip of that seal was not pristine. Bearing was still moderately tight in housing.

As you probably can deduce from my blog, I enjoy playing silly bugger with the syncro mechanics. Keeps me out of other trouble.

alistair

[HarryMann]

Bearing was still moderately tight in housing.

They're a strange one they really are. If you're getting rocking in the vertical plane but not lateral, it seems to be the housing, even though the outer races are apparently a tight fit.

[ragnarhairybreeks]

Harry,

thanks for the advice. I have the offending housing cleaned and painted as a spare. So I have the chance to play around with it, bearings, and stub axle.

cheers

alistair