clutch advice.

[Eddie010]

I always drive the flywheel seal in completly.
If I do it like in the manual, flush with the case it is always is not completly level and starts to leak after a few hunderds km s.

Ps love the website with the double seals... top.

[Bruce.m]

Typically the extra lip is there to keep dust / dirt away from the inner sealing lip, which could grind away at the lip & running face.

Elring seals have the ridges to “pump” the oil back but I’ve had better luck with a Viton SKF generic seal which is smooth.

[Bruce.m]

Found a photo of the case mod (Type1), if anyone is curious. Again…. I’ve not tested this myself. You can see the stock drain hole & how big the pool is normally

[raygreenwood]

Here’s a typical double lip seal available at seal shops in Europe. https://simplybearings.co.uk/shop/p7061 ... _info.html
Yes, it only has one garter spring and it’s Viton.

Yes....and even though they do not have a garter spring on the outer lip which is mainly a dust lip to keep dust off the main "sprung" seal inside....I think that if the 2nd lip is wide enough and stiff enough it could really help. The gist being that it "may" help to keep any oil that leaks past the main seal lip...in the space between the seal lips until it can drain back into the seal cavity on the liquid side.

From looking at a range of seal catalogs, there are a LOT of different double lip seal profiles.

Bruce.m said:

From recent T1 experience, with good synthetic I get a small amount of creep at the main seal after the car has sat for days. Typically one drop hanging from the bellhousing. I have also noticed both oil piston caps (relief & pressure valves) get damp. Those had new crush washers but needed a smear of sealant.

A feature that VW designed in was a bath of oil behind the main seal which goes over the lip. The drain hole where the shims are, is offset to the side so it doesn’t drain and leaves a pool of oil there. That oil creeps past the seal until the level drops below the lip. I assume this was deliberate to keep the shims wet for cold starts.

I discovered that Linse (German aircooled builder), cuts a thin grove in one case half from the base of that area to the inside of the case. It’s not very big but when the engine stops running the pool of oil can drain into the main sump. I’ve not tested this feature yet but I’ve added to a T1 rebuild I’m currently doing.

Yes, that looks promising too. One of the things to keep in mind is that IF we are venting our case properly, these are low pressure splash oil seals. One might be forgiven for wondering just how and why the heck they are leaking. I think a lot of that issue is axial play (in and out) of the crank.

I can guarantee that over on the Samba there would already be a bunch of people bitching that...."this is an awful lot of discussion about a simple seal that rarely anyone has problems with" ......I beg to differ. I drive 411 and 412. On my manual transmission 412 and on several 914's I have worked on...and I have seen just enough of it over the years from the bay window bus guys....to say that its a chronic problem.

For every 10 guys that have no seal issues on type 4 engines...I see one that does...repeatedly. Back in the late 90's when I drove my 412 all over 13 states (the region I worked in) at a rate of over 1000 miles per week.....for about a year and a half I went through right at 6 re-seals....for leaking...according to my log book.

I found better seals among the handful of brands we all use. I found better axial play/control/shims helped a ton. I made sure my case venting was spot on. I made sure my flywheel snout was not too rough and not too smooth (more about this in a minute). I went to the tropical spec silicone seal. I went to a 12mm vanagon tropical seal. All of this finally pretty much fixed it.

So....a few things about seal material. Yes, a viton lipped seal is probably best for motor oil. But, the tropical red/orange 100% silicone seal lasts the best. BUT....if you have ever used silicone wiper blades (yes they make them mainly for very cold and/or tropical climates)....they have problems just like silicone master cylinder seals would have problems.....when the surface they are riding on is TOO SMOOTH.

When the glass for silicone wiper blades is too smooth and there cannot reman a micro-film of water between the edge and the glass....the blase stick and chatter. This is teh same reason why for certain pneumatic cylinder types and brake master cylinders....silicone seals cannot be used. They wipe the excessively smooth surface TOO CLEAN and therefore do not have a microscopic lubricating film between the seal edge and the bore surface. They will stick and eventually tear the edge loose.

Likewsie...similarly....if your flywheel snout is polished too smooth, the red silicone seal will try to stick to it because a proper lubricating oil film cannot form between seal edge and sealing surface. In the case of the crank seal....the alternating sticking and breaking free at a high rate of speed....can cause seal lip vibration and flexing...letting significant oil pass by it.

I will have to inquire as to exactly what method of polish or surface profile is recommended. Ray

[Piledriver]

bumping to subscribe

[Keith Park]

well something you said Ray, made me check out the breather again, you helped solve my pumping the sump dry on long uphills by eliminating the breather on the left head, that solved that problem but when I checked out the remaining breather assy I noticed the hose going to the intake manif was collapsing, its that stock cloth covered hose so perhaps it wasnt breathing as well as it should but I replaced that hose and drove it 750 highway miles yesterday at 70mph or so and the clutch is has at least not gotten any worse, some drips around the bottom of the bellhousing so it still seems to be leaking some but not badly, probably about the same. I need to pull the engine at some point and do the clutch and seals, look at the galley plugs and try the few tricks mentioned here and hope.... I think the pressure plate is adequate though so long as I can keep any oil out of there. Ill wipe her down and see what drips up next week on the return trip.

[Keith Park]

I got the motor out, ALOT of oil everywhere, however the clutch itself looked rather dry, it might have some in it but not alot. turns out I have a 210mm clutch not a 215 and the disc I got is a 215 so Im totally boned until I can get a 210, have TWO of the 215's now that I cant use. I also got a 10mm crank seal when I ordered the 12, HOWEVER... I think this may be a better choice for me, the sealing surface in the flywheel is a bit worn, not bad but looks like this flywheel was bead blasted at some point so the surface was a bit rough and the seal shined it up a bit...with the 10mm sitting back in a bit it has a fresh unworn area to seal on, im thinking this is better... its in, used some RTV around the case seam, its bottomed out, Thoughts on using a 10mm in this scenario?
If I had to guess it was a galley plug leak, took them out, cleaned them, re-sealed them, new O ring but this time there was no oil on the flywheel bolts so I think that was sealing. now to get that 210 before it gets so cold out I wont work on it anymore.

Keith

[Piledriver]

For the gallery plugs, suggest using the permatex/locktite (same company, same stuff, different logos) anerobic pipe thread sealer, high temp. #565. hour or so work time, hard in ~ 4 hours, full cure in 24 hours. (at room temp)

[Keith Park]

THanks, thats exactly what I used, the 565, Raby included it in his kit to seal threaded items.

[Keith Park]

well the verdict it in, after 200 miles of highway driving its DRY! NO LEAK!
So either the leak was the galley plugs all along, or the new 10mm seal, fully seated, riding on a virgin surface on the flywheel is
doing its job now. Just glad to have it stay dry! Thanks for everyones help and advice.

Keith