Assembling 901/05 Engine- Phase VII-- ANOTHER flywheel seal change!

[304065]

"Himmel-herrgott-sakrament-zefix halleluja-scheissklump-verreckts!"

This was not uttered in my imagination. This, the Official Porsche Factory Swear, was uttered at the top of my lungs, with every fibre of my being. The object of my frustration was the flywheel seal of my 901/05 engine, now on its THIRD iteration.

Rewind to May, 2013. I had just replaced the SECOND "Victor Reinz" oil seal (one when I assembled, one when it leaked) with a KACO sourced from no less a personality than Dr. Ing. Steve Weiner, loud-pedal guru of the Beaver State. It's all here in gory detail for those of you with a strong stomach:

http://forums.pelicanparts.com/911-e...ms-change.html

I claimed victory. . .too soon. I drove 950 miles to the Parade in Traverse City with oil slobbering from the seal, all over the underside of the car, all over the the heat exchangers, where it baked on like hardened molasses. Fortunately for me, Dave Seeland lent me half a scotch-brite which made quick work of the crud, and the rest of my Concours was the stuff of history (repeated elsewhere here).

But now it was REALLY going to be fixed this time, in time for Jay Peak 2016. I had a three part plan:

1) Another new Kaco seal from Steve Weiner, he gets them from Wrightwood. Steve is awesome, he has been great help in this frustrating process. "Victor Reinz" is ancient Latvian for "compressed dog crap."

2) SKF Speedi-Sleeve, Part Nr. 99254. This would be installed on the end of the crank, both renewing the surface and increasing the diameter (slightly, by 0.5mm, so you keep the original seal dimensions) for an even better seal. No more excuses, if this leaks I'm splitting the case.

3) Factory installation tool P215 (Sir Tools.) I have used this twice before, I can do it blindfolded, and it takes the guesswork out of seal installation.

THE CHALLENGES.

First, the SKF 99254 sleeve isn't ready to be installed out of the box. It's too long, it's like 19mm long, if you install it without trimming it it hangs over the end of the crank and you can't mount the flywheel. If you cut it too short it won't locate on the seal's running surface. If you cut it slightly too long, the flywheel will rock on the crank because it can't seat.

Sooo. . .



This dimension, at least on my crank, was 17.5mm. The depth of the lip on the flywheel was 4.02mm. So If the sleeve was slightly less than 13.5mm from the driving flange to the end, that should cover the running surface and not interfere with the flywheel.

So how do you cut a .25mm thick stainless sleeve? A hacksaw? It would be properly done with a Lathe. Ed mentioned that he used tin snips and a file (,,,,, and 40 years of experience,,,, ) I don't have a lathe and am not planning on buying one this year. The local machine shop is owned by a nice, nice fellow. . . who ground my original flywheel . . .down to the wear limit. . . not going there again. I had to cut it myself, which meant. . .

. . . skateboard wheels. I am not kidding.

Don't ask me how this idea popped into my head. I was considering a mandrel of wood, somebody on the Internet used a block of UHMW Polyethylene (probably a medical device engineer) but ultimately I determined that a 65mm urethane skateboard wheel has EXACTLY the same dimensions as the snout of my crankshaft. . . and is flexible enough that the sleeve could slide on, and off once trimmed. So I sourced four of them (not much use for a three wheeled skateboard!) along with ABEC-9 bearings with an M8 ID.

I mounted the skateboard wheel on a leftover M8 stud and spaced it up with a few M8 washers. This was anchored to the base of a Dremel Drill Press (about $35) which had the ability to rotate the Dremel up to 90 degrees. With this I could fixture the sleeve on the urethane wheel, start the dremel, then cut a perfect line around the sleeve! This actually worked perfectly.



With the cut complete it was a simple matter to slide the sleeve off the urethane wheel, lubricated by some WD-40.



All that was left was to very lightly sand the cut edge to remove any burrs from the Dremel cutoff wheel. I think I went through four or five wheels, they tend to vaporize rapidly vs. the steel of the sleeve. Once so trimmed, I followed the installation instructions for the sleeve, which were to coat the inside with non-hardening sealant (I used Curil-T) and bang the sleeve on using the supplied installation cup. This took approximately ten seconds, and the sleeve was seated.



Once it was on, I verified that it was clear of where the flywheel would seat. The sleeve was 4.45mm away from the end of the crank:



And the flywheel lip was 4.02mm deep, giving me 0.43mm of clearance for whatever.

(Yes I know it's a Harbor Freight caliper, made in China, it cost me all of $9! I bought FIVE of these, I have them in every room of my house. I bought a "German" Mahr-Federal caliper, took it out of the box, guess what, made in China! So no more expensive digital calipers for me! The state of the art on these has long since passed and the accuracy and repeatability is sufficient for this type of work.)



The next step was to install the new seal WITHOUT destroying it. I wrapped some electrical tape around the crank to ease the transition from the P215 to the base crank to the sleeve, and lubricated the ID of the seal with some Swepco 15W I had on hand. I did not use any sealant on the outside of the seal edge, there are ridges on the OD to hold it in place and I didn't want to lubricate those with Curil-T. I tried the other THREE seals with sealant, this one I'm trying DRY on the OD.

On went the base of the P215, this screws to the crank with two M12s.



Once that is on, the seal slips over it and the cover for the P215 is screwed to the base, which pushes the seal home to a precise depth.



Once home, the entire P215 is removed along with the tape, and the new sleeve and seal are in place, ready to have the flywheel, clutch disc and pressure plate mounted up.



Well. . . that's progress for the day. . . if that doesn't do it, I will have to split the case to find out what the problem is.

Tomorrow: Mating the transaxle and engine installation. Enjoy!

[HarryD]

Wow, very creative solution. Hope it works out.

I had my 1973.5 motor get a top end from a trusted local mechanic. When it got it back, my pulley end was leaking oil like no tomorrow. I told my mechanic. We agreed using the flywheel external seal was the way to go as neither of us wanted to see the block split. Bring it home and it started leaking enough to make Capt. Hazelwood proud. brought it back and a tried seal #2. 500 miles later and dry as a bone.

Hang in there dude. Apparently this is one of those thigns that is easy in principle but a art to do well.

[Jon B]

Rewind to May, 2013. I had just replaced the SECOND "Victor Reinz" oil seal (one when I assembled, one when it leaked) with a KACO...
http://forums.pelicanparts.com/911-e...ms-change.html
I claimed victory. . .too soon. I drove 950 miles to the Parade in Traverse City with oil slobbering from the seal, all over the underside of the car, all over the the heat exchangers, where it baked on like hardened molasses...

If oil is passing between the seal and crankshaft, it will usually end up on the flywheel and be thrown in all directions. I don't see evidence of that in your Pelican thread- just a small pool of oil in the transmission bellhousing.
That would have suggested it was either leaking around the seal, or through the case halves above or below the seal.

Was oil being thrown by the flywheel this time?

Jon B.
Vista, CA

[304065]

Jon, the flywheel was acting like a centrifugal slinger, throwing oil everywhere. There was a huge amount coming from the aperture for the throw-out lever: it was blown by the slipstream all over the heat exchangers. I hear you on the alternate pathways. . . and was very suspicious of leaks-- but there is absolutely no oil above the crank, in fact the 574 is intact along the entire parting line. When I removed the flywheel there was a clear puddle of oil on the bottom of the crank around the seal, suggesting that's the origin. But you could be right. Didn't the Factory put additional studs in this area with the magnesium engines?

[mobius911]

You definitely win the MacGyver award for this month! Hope third time's the charm.

[Jon B]

I don't see evidence of that in your Pelican thread- just a small pool of oil in the transmission bellhousing.

I was basing my comment on the picture from your Pelican thread, below.
It didn't appear as if oil was being thrown around by the flywheel at that time.



Jon B.
Vista, CA

[edmayo]

I like the skateboard wheel John,,,,I'll keep that one in mind. The best seals are of course no longer available, they were white silicone, I had a couple set aside that I've used on my stuff. One of the worst seals I had was from Porsche for a 993 turbo, did that one twice before Rosemary at Wrightwood told me they were junk and to use the brown/black SC seal. Bingo, solved. Sometimes no matter what you do it comes down to the seal itself,,,,and they all aren't made equal. I also will not use Reinze anything.

[304065]

Epilogue:

Never one to leave well enough alone, I decided to replace the shroud with the latest and best from Damon at Series900. And as a bonus the "shroud whisperer" was actually passing through and helped me trim and install it! (And also narrowly avert the car falling off the jack. . . thanks again!) The new shroud is indistinguishable from the original. . . with the exception of cracks, blemishes, indelible oil stains and 50 years of heat soak.

I also took the opportunity to have Shaun Budka at Tru6 replate the engine fasteners and a few other shiny bits. . . he did an amazing job and went way beyond my expectations in terms of level of service and attention to detail.

For the pundits. . . yes I know about the plug wires, they are the "driver" set, the original Beru will be going on later. . . and of course there are a few other small items.. . can't wait to throw the fuel to it and see if my exertions have solved the leak. . . .Ich Wunsche der Gluck, tu einen neuen Gang auf!

[dummkopf]

Where there is a will, there is a way!!! Nice job and thanks for sharing!!!

BTW google translate didn't do a very good job at translating the "phrase" in your first post!

[304065]

Ach! Do you see those puddles of oil beneath the car?



Oh wait, there aren't any. . .