Rear Main Seal Replacement-Which is better?
 

My rear main Porsche brand seal (flywheel end) just started leaking on my new build. Bummer!!!
Our host sells several brands. There must be other brands out there as well. So, which one is better?
Cheers,
Johan

the brown one

Both the Reinz and Elring seals appear to be "brown". Any idea which one you are referring to? Here is the link.
Pelican Parts - European Automotive Parts and Accessories - Porsche • BMW • Mercedes • Volkswagen • Audi • Saab • Volvo • MINI
Thanks,
Johan

I use Kaco seals. No Elring or V-R, ever.

Thanks Steve for your valued recommendation. Went on Kaco's web site- quite impressive. Kaco's it is!
Cheers,
Johan

You are having some bad luck. Did the JB Weld on the case seam hold?

The JB is holding nicely although now camouflaged by the oil from the rms. #>%*+#
johan

Kaco seal.
 

Thanks.

I can't find the Kaco seal for the 66mm. Crank.?

Thanks - Cheers - Olsen911 - Tommy Olsen

I hear a lot of bashing of Victor Reinz in the forum. I used the Victor Reinz gasket set from our host when I rebuilt my 3.2 a few years back. I have had no issues with their sealing. Initially I had a leak at the rear main seal, but it was due to setting the seal too deep. I replaced it with another Victor Reinz seal, this time set slightly shallower, and it does not leak.
Perhaps the other brands are "better" but I believe many of the issues are from the installation as opposed to the Victor Reinz seals lack of quality.

Over the years we've had the opportunity to test many different manufacturers of almost everything 911 engine related and I can tell you from experience that many of the Victor Reintz products are TRULY inferior.
We use enough products to actually do side by side comparisons.
In some, very few instances the products are similar but the majority of VR products are what we consider, unusable.
There are times, the last time was a few months ago, when we find ourselves desperate for a gasket or two, (the last was 3.0 head gaskets) and we picked up a few from a local shop. Upon inspection, it was determined that the VR they supplied were crap. We elected to wait a few days in order the get a quality product.
A friend built a 2.4 S engine for a very expensive show car, most of you probably heard about this record setting sale and with a few hundred miles the engine was back to his shop with leaking heads. Upon inspection, (simple measuring) we determined that his issue was over sized CE rings. That's right, VR rings were manufactured way too thick......
Oil leaks suck so why take a chance with marginal products?
For crank seals front and rear we use Elring or Kaco depending on the fit requirements.

Henry, I have no doubt about your opinion, and I am not endorsing VR products. I have rebuilt quite a few engines, but only 2 were Porsche, so I would never compare my knowledge to yours. I trust your experience.
Recently I was asked by a friend to check out a Model A engine he had purchased. He was told it was just rebuilt by someone with a a lot of experience and was ready to run. Top quality parts were used. I found the main bearing clearance was too tight, and would have ruined an otherwise nice engine if run as is.
I was successful with VR on my 3.2 and 2.4 rebuilds, but in the future I will use other brands from reading recommendations of more experienced. Interesting to note is your preference for Kaco and Elring, and Steve's "I use Kaco seals. No Elring or V-R, ever."
My point is that it is important to make sure that proper assembly and clearance checks are done. It is easy to blame failure on a part, but a failure can occur even with quality parts if not installed correctly.

My point really isn't good, better, best or will it work?
My point is always, what are your/our best chances of success.
I don't care what it costs or what "band" it is.
I always try to use a part or technique that has demonstrated that "best chance".
Of course, attention to detail will generally yield the best results but if a lack of experience leaves someone with less opertunity to compare parts quality, the best technique in the world, can still generate a "do over".
From my point of view, that is a failure I can't afford.
As I stated, Kaco or Elring and the reason is that Kaco doesn't always produce the gasket or seal I need. I'm always more concerned with the appropriate application than band. If Victor Reintz made the only product for a certain application, I would use it. Then look to find someone who would produce what we need.
That's how the whole "Head Stud" process started.
No one made a head stud that fit our requirements, so we enlisted the advice of experts and proceeded to fill the product void we encountered.
Since then we have produced a plethora of products that we couldn't find anywhere else.
In some cases, someone else started producing an equal or better product and at that point we stopped producing ours.
We want to build the best engine we can (as dictated by the build sheet) and only build the parts we need to do just that.

I'm resurrecting and updating this thread.
But first a correction to my original post. My leaking RMS was not "Porsche brand" but rather made by Victor-Reinz.

Here is what I thought was the only culprit. Note how the inner lip is curling out.
http://forums.pelicanparts.com/uploa...1487789497.jpg

After seal removal and cleaning, I also noted that it is likely that there is also a leak originating at the lower seam.
http://forums.pelicanparts.com/uploa...1487789497.jpg

I got a replacement Kaco seal from our host but it is black acrylic rubber and not the all brown all Viton FPM which I understand is the preferred seal according to fellow Pelican Henry Schmidt.

So my questions to the brain trust are:
1. With what do I seal the seam gap outer (vertical) edge which remains exposed after installation of a new seal?
2. Should I spring for the Kaco brown all Viton FPM.
3. Looking at the first pic, did I initially correctly place the seal. It's about .5mm in from the outer (vertical) edge.

Thanks in advance.
Johan

Hey Johan,

Sorry to read your troubles.

Just my opinion:

1. There is really nothing you can do about that seam, because the prior rebuild probably did not insure case was straight before mating the surfaces or worse let the sealant to go bad. Sorry.

2. The Brown Kaco seems to work better but it will not help if it is leaking from the above seam.

3. Too deep, it supposed to be 0.5M above the ring.

My 2 cents.

You know what, my RMS leaked crazy too ultimately taking out the clutch.

VR seal...

DRACO,
1. the case halfs are straight and are mated properly. The problem is that sealant was not brought out all the way into the outer lip. Still pontificating what I should use to plug.
2. Yep, Brown Kaco it's going to be. Hope I can get it locally.
3. So to be clear, I should have placed it .5mm OUT from the vertical face of the lip. Correct?
Thanks for your help.
Johan

If i remember correctly, LocTite makes a "wicking " product that might help with this issue.
Of course getting it thoroughly clean will be the challenge. Acetone in a pressure sprayer might be an option.
Good luck

I think your problem may be more to do with the case as the seal material will only affect longevity.

Seal Materials and their speed ratings are interesting and are important.

Assuming a P-V of around 1 and a 65mm diameter shaft the maximum running speeds for the various materials that are available should be as follows:

Nitrile (NBR) 2750rpm - at higher speeds the seal will run hot and wear very quickly.

Acrylic Rubber (ACM) 4750rpm again higher speeds will cause rapid wear.

Viton (FKM/FPM) 8500rpm - I would consider this to be the only suitable seal material for this duty.

The tension in the lip is also important and the lack of radial compression on the body of the seal is probably the main culprit.

The seal has the nominal dimensions of 65 x 85 x 10 and the diameter of the housing needs to be 85mm with an H8 tolerance.

If the bore is larger or is not concentric to the shaft you may well experience problems and it looks as if the seal doesn't locate correctly on the shaft.

If the bore in the case isn't round and is our of tolerance I am not sure you will ever solve the problem without some machining work.

I feel you may have to split the case measure the bore and then decide the course of action.

Hey Johan,

Oh geez, okay.

1. As you might know if 574 was used by PO/builder, any protruding/exposed 574 would desolve away. Gosh, I hope I am making sense here. I like Master Henry's suggestion above. Try that.

2. Good :-) I am sure you can find it.

3. Yes, lip of the case.

Jim

I thought years ago the "hot setup" that Wrightwood touted as the best seal is the black and brown. Black and brown is Elring-Klinger. Has that changed? I haven't bought a Wrightwood gasket kit in a while.