Unstoppable flywheel oil leak on a vintage speed 36 hp engine

[philippe1]

Good evening everyone.

I changed my 36 hp flywheel for a new one! Who no longer has play at the dowel pins . Everything is perfectly adjusted, no longer play at this level, but despite everything the continuous oil leak.!!!

Nothing makes it change of seal single or duela lips, blue or brown...
it's the same!
I cannot stop thinking about the leak at the seals (c am plug is fine )
it makes me crazy
I checked with a gauge and
I have a hot oil pressure at idle 2.5 bar and 3 bars at 3,000 rpm

Can too much pressure cause permanent leaks?

any suggestion welcome

[hazetguy]

do you have the paper gasket (with light coat of sealant) between the flywheel and end of the crankshaft?
is the flywheel fully seating against the end of the crankshaft?

edit: the "light coat of sealant" i use is Curil-T worked into the paper gasket.
i always use a paper gasket in that location.

[esde]

I have had to use some sealant with the paper gasket... once.
Or, there is a drain hole behind the seal, where oil is supposed to drain back into the sump. Could there be a piece of trash in the hole? I've seen guys use excessive case sealant and it blocked the drain.. with the same unstoppable leak. Or measure the flywheel seal surface, is it the same as the old flywheel? When the problem is strange you need to look at everything...

I did have a leak once that I could not find because the exhaust was in the way. So we pulled the engine, and stripped it down, and then used a pre lube device to put pressurized oil in the passages. And there it was right where I didn't expect it.
_________________
modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[philippe1]

Thanks both for your answers
Yes the drain back hole is ok and not blocked
I tested it
In between the flywheel (WW 69.5) and the flywheel AA performance I used the thins metal gasket and a a specially machined flat shim sealed with silicon to tighten the 36 mm nut….
I will investigate tomorrow to check if the relief valve is not blocked cause I have 2,5 bar as pressure when engine is hot
Obviously a bit too much but not excessive !!!
I do not know what to check after that and will probably disassemble the whole engine

[[email protected]]

Have you checked the oil cooler..

[philippe1]

[[email protected]]

[philippe1]

True I understand
Fact is that on the stand all seemed fine and leaks appear after a short drive and with oil hot..
My guess
I installed an aluminum 356 cooler that looked good and I think ( not sure) have it pressure tested before installation
I will investigate today in this direction..
After that I simply put this crazy engine on the shelf and re install the original one

[esde]

What oil pump did you use? Oil weight?
_________________
modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[RWK]

I would also check flywheel run out at the seal surface, check crank also.
_________________
73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530

[RWK]

Did old flywheel leak?
_________________
73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530

[philippe1]

hi all

with the previous flywheel drilled in 8 dowels pins (he had play) the engine leaked a bit also!
I checked radiator and it is perfect...
flywheel surface is fine along with the crankshafet surface..
i have a big oil pump (30 mm) may be it is too strong and cause the heavy prseeure (3 bar cold 1500 rpms)
i will come back to a 26 mm original oil pump plugged for full flow,,,,,

Last thing before removing the engine and check if the lieak comes from behind the flywheel..
if so it is for sur the seal
I will try a viton single lip , suppose to be the best ones..,

[philippe1]

[Alstrup]

Stop stop stop!
1. A 30 mm oil pump is WAAAY too much in a 30 hp case. (Unless you use 5/W30 oil of course) 26 mm is plenty, and even then it is best with a pressure/volume relief cover. Remember, a stock 30 hp oil pump is only 20 mm. IIRC.
2. I assume it is an AA flywhell. There are 2 models. 1 for use of a late model O ring, and 1 for use of the paper gasket. Verify which you have and which the flywheel was designed for.
3. Are you sure you are using the correct oil dip stick? I have seen people swop for a newer type 1 dipstick. This results in them unintentionally having about ½ l. too much oil in the sump. This results in oil spilling too.
4. Some of the AA flywheels are too small on the seal diameter, so the press against the seal is too low. i have fixed that by machining the flywheel for a crimp on bushing so the flywheel diameter becomes correct and gets the correct press against the seal.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[philippe1]

[mukluk]

[PeteSC]

I agree with this.^^^

I had the same issue about 6 years ago. I believe I used a metal crush gasket for the flywheel/crank mating instead of the paper one (if memory serves me correctly it’s a 356 item, link below), with a thin coat of Loctite on each side. No issues since.

https://www.autohausaz.com/pn/10836936-50202301?ut...gLQGvD_BwE

[wagen19]

[philippe1]

[philippe1]