clutch advice.

[Keith Park]

I have a 2056 (2L 914 based) in my squareback and Im having a lot of fun with it now that its tuned and all the bugs worked out,
However even when it was new and clean I always felt the clutch was Barely adequate at best, now I have a small oil leak
In that area and it may (or may not) be influencing the clutch as it slips when I get above 75 or so and floor it, once the motor
Is putting out HP. I hate stiff clutch plates and all the things that can break to operate them, but is there a “next step up” that I should
Implement OR a different disc? This car is just an everyday driver, never raced, mostly highway miles.

The other issue is that the plate was balanced and a new one wont be and that isn’t good…

And in a related question, I seem to often have a front main oil leak, not bad, never SEEN it in the clutch when things were apart but there are a couple drops after
A long highway trip. Victor Reinz 12mm mail seal, that seemed OK last time the motor was out but when I pulled the flywheel bolts they were drenched in oil, which told ME
That its an Oring problem, correct idea? I did put a new Oring in there (and mainseal) last time but still some seepage. Galley plugs were done on this when it was rebuilt.

Thoughts or a sermon anyone can point me to on the front main oil issues? Its never gotten into the clutch before but I think there might be a little in there now.

Keith

['77 Westy]

Oil may be passing the seal at the split line; I used a smear of sealant just at the casing join and (touch wood) have never had a leak.
I have a standard 228mm clutch in my 2316 pushing a heavy Westy and it doesn’t slip. You could use an uprated pressure plate with a standard friction plate but then there are the potential problems that you are concerned about.
I have never, on any engine, balanced the pressure plate with the flywheel for the very reason that it couldn’t be changed.

[raygreenwood]

I have had less problems with Victor Reinz seals than Elring and others even after I finally grasped the 12mm seal difference. I believe its probably a minor issue with seal lip profile/tension and surface profile of the flywheel sealing surface itself.

But...I feel that sone of this also has to do with spring tension. Some of these seals havesmaller diameter hose springs inside.

From speaking to a lot of people, I also feel like we are getting the snout on the flywheel either grossly too smooth or too rough. Many suggest a couple of spins around with 360 grit crocus cloth/shop roll.

One thing I have also seen and wondered if it may help....is going to the double seal method. The seal dimension is 75 ID x 95 OD X 10 or 12mm.

I am wondering if a 75X95X 5 or 6mm ...two of them stacked....may end this problem once and for all. Thse are called "skeleton oil seals". At one time AC.net and others sold these in sets for type 1 for racing.

As for the pressure plate balance. Take the complete flywheel down to a balance shop with both pressure plates. Leave the old one attached to the flywheel and marked. They can spin that and get an idea of how well its alanced. Then slap on the new pressure plate and balance teh complete assembly but instruct them to ONLY remove material from the pressure plate and not the flywheel. The flywheel is sodwel pinned to the crank to go back on in the same position. Ray

[Keith Park]

thanks for the advice on balancing the pressure plate, makes sense! now to fine a slightly stiffer plate if it exists.
last time I had the engine out it didnt SEEM to be wet behind the flywheel, more at the bottom of the bellhousing than anything else but the drippy flywheel bults told me Oring, but thats a new one on there now. Sounds like the front main seal on these engines is quite the problem

['77 Westy]

A double lip seal could be used but I doubt if there is an advantage in fitting two single lip seals.

Sachs and KEP HD pressure plates are available for the 228mm clutch.
https://gowesty.com/products/pressure-p ... 3041645733
https://thevdubfactory.com/products/clu ... BVbPh0GYmp

[Keith Park]

I have a 215mm Stock 2L 914 clutch.

[Bruce.m]

Has the flywheel ever been machined?
There is a tolerance for the depth between the bolt surface & the friction surface so both need machined if it’s getting resurfaced.

[Keith Park]

No, other than balancing.\
Im just trying to get a handle on this problem that sounds like its more of an issue with the T4 motors than the T1's, I thought I had everything just right last time but still leaks, and this time into the clutch. so with a leaky rear main how does that get into the clutch, or am I more likely looking at another O ring issue? is a leaky O ring more likely to contaminate the clutch?

So, 12mm victor reinz, bottomed out, smear of RTV at the case seam going in, any other tricks?

[oprn]

Been there, done that. If the leak is ignored long enough the volume of oil in the bellhousing area builds up to the point that it drips off the top of the bell housing onto the pressure plate, throw out bearing and transmission input shaft and migrates onto the clutch plate when you shut the engine off. At that point it is impossible to tell where the leak originated. I too blamed the main seal but after changing it twice and buying another flywheel (to get a fresh seal lip surface) and having the same thing happen all over again I discovered the leak was actually not the seal. It was the oil gallery plug that feeds the lifters.

Now that is a tricky thing to get to seal up due to the fuel pump push rod bushing being so close to the back of the case. I could only get 2.5 threads in that hole before the tap bottoms out against the brass bushing. I tried sealers of different kinds to no avail. It finally stopped when I shortened a pipe plug to about 1/2 it's original length and screwed the fat end in.

As for the pressure plate upgrade, yes my Bus 210mm pressure plate feels very soft on the clutch peddle but I find it holds the power of my 1911 just fine. Until it got oil on it... then it slipped at 60 mph on the road. I cleaned the pressure plate and flywheel really well with brake clean. I soaked the clutch disc in gasoline overnight then cleaned it well several times with brake clean and put it all back together. It's still holding just fine 3 years later.

[Keith Park]

Yea, there's plenty of oil flung around in the bellhousing but only a little drip or 2 after a big trip. I had the galley plugs done from "A reputable shop" so havent really considered that, but its possible. when the motor was out in the spring it looked pretty dry backside of the flywheel, but the excessive oil dripping out when I removed the flywheel bolts told me "I found the problem!" and I replace the Oring and thought I was home free... I SHOULD have said "I found A problem" and maybe there is something else. Ill have to look into them when I pull the motor again to once again, try and fix the oil leak... in the past it hasnt contaminated the clutch but this time it has. the slipping was a bit less on the 100mi trip today, but Ill have to get in there again soon.

Keith

[oprn]

It wasn't until I gave up on the leak , resolved to live with a small drip and ran the car for a couple of months that enough oil got in the bellhousing to finally drip on the clutch. Then the clutch started to slip and I HAD to find it. When I took it apart the backside of the flywheel and everything behind it had the same light coat of very clean oil. Made it impossible to tell for sure where it was coming from.

This might not be your problem but keep it in mind as a possibility.

[Keith Park]

well I ordered up new seals, a new disc and even a throwout bearing and will dig into it maybe later this year or the spring when the weather permits, its not fun pulling a T4 out the back of a Squareback but I do have the procedure down pat. was out last spring when the input shaft bearing on the transmission nearly grenaded. this time Ill be a super prick about ANYTHING that could possibly leak. It doesnt drip much and I too have lived with it just surprised that it finally got in the clutch. When the Stock T3 engine was in the car some 30 years ago the main seal went and it dripped quite a bit before the clutch got contaminated, maybe this synthetic oil is slicker than that old Dino stuff.

[raygreenwood]

well I ordered up new seals, a new disc and even a throwout bearing and will dig into it maybe later this year or the spring when the weather permits, its not fun pulling a T4 out the back of a Squareback but I do have the procedure down pat. was out last spring when the input shaft bearing on the transmission nearly grenaded. this time Ill be a super prick about ANYTHING that could possibly leak. It doesnt drip much and I too have lived with it just surprised that it finally got in the clutch. When the Stock T3 engine was in the car some 30 years ago the main seal went and it dripped quite a bit before the clutch got contaminated, maybe this synthetic oil is slicker than that old Dino stuff.

Yes....the synthetic oil is slicker than dino oil and can contribute to a small "seep". Over the years, a ton of people have been saying that the synthetic oil causing leaks is a myth. They are totally incorrect.

The point I am about to make also goes back toward my comment about using a double seal. The double seal sets used to be sold on AC.net at least for type 1. So its not just a different idea. Its been used for various reasons.

You mentioned why not just use a double lipped seal? Have you searched for a douple lipped seal in 75X95X12? Its hard to find.

Then when we do find one, it starts getting into the issues of what it is made of. Most you will find are NBR (Nitrile butadiene rubber). Pretty good stuff but not ideal for automotive...especially with ester based synthetics. Viton is a little better but you really need silicone for best resistance.

The other issue is the proper lip shape for speed and axial movement. I do not know enough to say what is the perfect lip design. But I do know that the materials, oils and geometry that worked when our cars were originally built...have issues with modern oils and might even have issues with modern production tolerances.

Ther other problem with dual lipped seals is that really the outer lip is not the same profile as the inner sealing lip. It also has no garter spring. It is really just a dust lip. It keeps dust off of the main inner garter sprung lip. Not saying thats a bad thing at all. Just that it may not be doing what we think we want it to do.

One of the most important things I have found that can keep the annoying mystery leak from coming back on type 4 engines....other than finally discovering the issue with using a 10mm seal in a 12mm seal cavity......is that the design of some our seals.....does NOT tolerate much in and out axial movement.
I found that when I kept my crankshaft shims to the absolute tightest safe tolerance....the leaks pretty much stopped. I work to keep my flywheel shims set at 0.003". That made a huge difference.

A part of this problem goes back to seal design. You know those little radial fret marks you see on some seals and not one others? Those are DESIGNED to allow and work with axial shaft movement. There are numerous design effects.

This is a nice PDF download that explains seal lip designs and oil pumping "effects" designs I was just talking about. That conversation is kind of enlightening and starts on page 4 of this PDF. These marks or engravings are designed to help "pump" fluids back to the liquid side of the seal.
NOTE: some of these features are "bi-directional"...andsome only work clockwise or counter clockwise. Do we even know if our seals have the right surface features for our crankshaft rotation direction?

NOTE: to make that link work....copy the whole thing and drop it into google and it will pull up a PDF for NAK sealing technologies in Taiwan. Very nice download

file:///C:/Users/jsgrn/Downloads/Training%20Chapter%204%20-%20Seal%20Type.pdf

Its also worth getting down into the seal design/cross section pages. Down on page 19 they have some interesting seal types with one main sprung lip and TWO outer lips.

All I really know is that when we shop for flywheel/crank main seals...we shop by part number and by what is available at the various VW shops.....and we do not actually shop by application at a seal shop.......asking and answering all of the questions there would be when one is "specifying" a for a new application.

I have never done that and some day....I plan to.

Drop in a seal shop and say....I need a 75mm x 95mm X 12mm seal......for going into an aluminum housing....using a synthetic ester based oil....at 250* F....with a rotational speed of 476 inches per second constant (relates to 3000 rpm) and 872 inches per second peak (relates to 5500 rpm)....with maximum axial play/movement of +/- 0.003" or +/- 0.004"....and we want to keep this very dry leakage wise. See what kind of seal design and material that request set generates....and....ask what type of surface polish/profile is required for that seal to run with.

Ray

[Bruce.m]

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.

['77 Westy]

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.