Flywheel seal failure x4
 

I have replaced my flywheel seal 4 times. It has leaked each time.

Is it possible something is wrong with the oil return passages right behind the crank flange(main bearings) causing a local high pressure buildup?

It is leaking around the crank, not at the case.
I measured this last time with a caliper to ensure it was installed square to the crank.

I read this awhile ago and had it done when my rebuild had a leaky seal. Do a search for more detailed info.
The crankshaft winds up with a tiny ridge where the old seal ran for years. In order to get the ID of the new seal to fit tighter around this worn area you need to modify the seal. The spring can be removed and the ends can be freed. A small amount of spring length is removed and then the spring loop is reconnected. So far this has worked well on my car.

tried it on the third seal.

Crank has no groves or ridges, i ran a fingernail back and forth around it to check.

Are you using factory porsche seals or aftermarket?
I found the factory porsche black ones to be superior to the brown aftermarket ones on my 3.6 rebuild.

Kirk

You guys figure out how to get it to seal - LET ME KNOW!!!!

Every single one I've ever installed has leaked - not a ton, just a constant drip kinda thing...

Chicago Rawhide and other companies make a type of seal that has more than 1 sealing edge.
I have used some of these in other types of engines (V8's etc).
The difference in these seals is the horizontal position of the lips.
They have to accomodate 2 or more lips, so they space them at different positions from the original seals.
They also have inner and outer lip seals available ( to keep dust out as well as oil in).
You might want to check this idea out.
Bob

I will first assume that you have read the other posts from the search function as that is ultimately how I solved my problem.

The first install had a problem with a small burr/lip where the cases joined. The second install after I cleaned up the burr leaked due to installing the seal too deep and apparently blocking the oil drainage holes.

The third install worked perfectly. I used the orange seal, coated the O.D. lightly with Curil-T, then carefully installed it flush to the lip of the case. No leaks.

Unfortunately, after having a leak free engine for the first time - ever - it began to smoke. The teardown has revealed heavily worn oil rings and lots of metal particles running through the oil leaving the valves, pistons, and probably all of the bearings terminally damaged. :(

yes I searched, and read and read. I am using the brownish ones. Mine drips about 3 drops a minute at idle. When parked though it all runs out of the bellhousing leaving a large stain, and making it look worse than it is.

I am at the point of tearing it apart just to seat it again when the case is assembled.

i think i had replaced mine about 4 times before it finally took. i stuck with the Victor Reinz seals. this last time, i tried every trick i had heard of:

1: shorten the spring by 1/4 inch. remove the garland spring. unscrew the connection joint. cut 1/4 inch off of the non-tapered side. pre-load the spring by twisting each end CCW, then screw the ends together. (you don't want to the spring to try to unscrew itself)

2: Buff crank journal with 0000 steel wool to haze it

3: Super Black RTV on the outside of seal

4: Oil on the inside lips of seal and crank surface

5: Determine previous install depth(s) by using depth caliper. Determine max depth allowed before interfering with oil passages or crank flange. Set seal to new depth.

good luck

gorilla glue

maybe it's something else..............?

Have you measured the outer diameter of the crank, compared it with the Porsche spec and then the seal inner diameter. What is the compress rate.
Is it possible that you crankcase housing is slightly oval. Measure that as well.

There are new technologies on the market called PTFE seals. The lip is faced to the flywheel not to crankshaft. The performance is much better. Suppliers are Hutschinson, Freudenberg, Sabo Kako,Bruss etc.

That sounds like the problem all along... a worn engine and excessive crankcase pressure....
Did you ever do a leakdown before working on the leak?

Quote:

" Unfortunately, after having a leak free engine for the first time - ever - it began to smoke. The teardown has revealed heavily worn oil rings and lots of metal particles running through the oil leaving the valves, pistons, and probably all of the bearings terminally damaged"

I had a fellow Pelican come to our shop with the same problem. He installed the seal correctly but did not clean up the excess case sealant around the outside of the seal area. After cleaning up the excessive case sealant on the case it sealed just fine. See pics http://forums.pelicanparts.com/california-southwest-us-az-nv/366345-bap-look-here.html

years ago i did one on a 2.7 engine and it gushed quite nicely. upon removing the engine again to check it out, i found that the flywheel/crank could be moved around about 1/4" in various directions by working it with a screwdriver on each side. badly worn case on that one, among other things. now i check that as a matter of course.

I am sure the problem is the crank or case. I checked the main journals but not the case seal bore. It is coming apart in the coming weeks. And yes, it would have been better to check BEFORE I rebuilt it!

Not to hijack...

Yes, I did check leakdown before tearing the engine apart but the results were good due to the compression rings still doing their job. The ring thing was a little weird and unlike anything the machine shop has specifically seen before.

Kinda like the hybrid old/new intermediate shaft assembly that had the gear come loose and required me to split the case last time! They had never seen an intermediate gear attached to the shaft with two pins AND four bolts. Hopefully the ring thing is the last of the irregularities. :rolleyes:

Good Luck DWEYMER!

I will update when I get it figured...around xmas prob! :)

Christmas? Nonsense Donny, you're in Raleigh now. We can have that torn down in a morning, ship it off to your favorite 911 machinist, have it back together in a few weekends.

BTW, want to check out a trans rebuild? Planning to do a mag-case 915 next weekend.

I have a line on an already machined case. I just have to be sure the case is the problem. PM me details on the trans rebuild, I am not sure about my schedule right now, I do know of at least one other person who would love to see that.


Oh, and to add to things, I just bought a '44 cup car that needs a lot of TLC, and a complete re-wire. Picking it up tonight.