Hello everybody,

I the last weeks I had a few contacts to Porsche Dealers in The Netherlands and Germany, to have some more info about the date/engine numbers that have a Luk Flywheel or not.
This info is given me by Phone, and I have 1 copy of a parts computer programm [Porsche PET]wich was sent by fax to me from a Porsche Center in Germany [I promesed to say or write no names]
The Porsche parts man told me that Porsche fitted the Freudenberg problem Flywheel untill July 1991, an replaced it for a better kind of flywheel [in between flywheel] in August of 1991 for the Model Year 1992. Part Number *96411401201 for code nr. M64.01 c/M64.03/M002 The "frequently talk about" Luk Flywheel was first fitted in 1993.
I think I get more info thru this week about "service info's" about the whole DMF History.
I try to share this with you all.
Please notice: this info is unofficial but 95% reliable!!!]
Hope this helps a lot of people that have questions or are deperate.

The reason why I investigated this part is, beacause I have a 1992 C2 from March, and wanted to know what the future repairs would be so I can prepair for costs.

Arjan
[excuse for evt. Language faults]

 

Dear Arjan,
I am afraid the information you have received is not entirely accurate. That may well have been the plan but in reality many 1992 models of 964s still had the old DMFs installed. No 964 C4 for instance ever left the factory with a LUK installed until the 1994 model year. They could be retrofitted. Also depends a lot on what production line. The USA line tended to get the changes first, then the ROW when existing stocks were exhausted. This was Porsche policy. Another part which fellinto this category for the ROW only was the DME. The only way to really know what your flywheel is, is to check physically. I do not recommend you rely too much on parts catalogues and production line cut in dates for such things.
If you have a LUK installed, you will not have any flywheel problems in the future anyway. Clutch quite possibily but not the flywheel.
Ciao,
Adrian.
911C4

 

Thanks Adrian,

I said before, the information came from a German Porsche Zentrum, and the helping man is a very experienced Porsche specialist.

As you will know, it's very difficult to get any sort of information from Porsche Dealers, because it's prohibited by Porsche.
Anyway, I get this week more information, inculding Porsche service bulletins with the correct info about DMF's and engine numbers, they promesed me that. Porsche sent more then once different versions of bulletins about DMF's out in those days.
As I get the faxes, I let it know.

Anyway, 135000km's with a factory fitted Freudenberg flywheel would be unthinkable, wouldn'it?

I had some E-mail contact with Bruce Anderson, the famous writer from Porsche books.
He wrote in one of his books , that Porsche installed the Luk DMF in May 1992 and from engine number 62N01738.
Tipical is that my Porsche C2 has a engine number that starts with 62N05xxx and was produced in 1992 March.
I told him that, and he said, may be there is a fault in that information, and he wants to know my progress in my search, and let him know if I made any progress.

I try to get more clearance in things, because everybody tell a different story.

I send you the Copy of the parts print in private mail.

Thanks again, and.............Have a nice Sunday.
Arjan

 

Dear Arjan,
Bruces data is correct and is supported by a large number of documents I have. All from Porsche. N series engines were used in 1993 model P series 964s as well. In fact this started in January 1992. It is a very confused period of time. It is quite possible that you were lucky enough to get an engine (based on your serial number) which was modified up to 1993 spec.
I have all the data all the manuals and all the Service Bulletins and the parts catalogues thanks.
Production lines are somewhat confused places and the records are never accurate.
Anyway, 135,000klms out of the original DMF is not unheard of. Unusual but not unheard of. The Technical Service Bulletins are all online and available for a very low price,
Ciao,
Adrian
911C4

 

Hello everybody,

I promesed you to come back this week with a answer on the Luk dm flywheel.
Today, I recieved a message from Germany, that my car, a 1992-March 964 Carrera 2, with engine number 62No5xxx had no Luk dmf fitted by factory.
This is a car made for Europe, and for the country Italy.
This is a not so nice message for me, so I have to be prepaired for my "Bad day" when my Dmf will go down.

More info I could not get out of Germany, only that they first used Luk Dmf for Europe in Model Year 1993.

Sorry,
Arjan

 

Hello everyone,

I traded several e-mails with Arjan on this topic, and--if you didn't catch this from his posts--he has made some interesting observations:

-His car was "born" 3/92, engine serial number 62N05xxx.

-Bruce Anderson has written in his Performance Handbook: "it [the DMF] was replaced in May 1992 by the 'LUK' dual-mass flywheel which seems to be much more reliable. The flywheel change was made at engine number 62 N 01738. The N stands for model year 1993."

-So ... Arjan's engine serial number is after that which should have the LUK, but his car was made before the LUK implementation date. My intuition tells me the engines should be installed as they are produced, so how could Arjan get an 62N05xxx engine in his 3/92 car, if engine 62N01738 isn't produced until May of 1992?

-Arjan received information from a Netherlands dealership that the actual LUK implementation engine is 62N07138. This would imply that Bruce's source of info (or his book) has a typographical error--the 1 and 7 being swapped.

-This would also be consistent with Arjan's engine S.N. of 62N05xxx--that is, approximately 2000 engines were produced between March and May of '92.

-Arjan traded e-mails with Bruce Anderson, and Bruce wrote the following to Arjan: "I think that your Porsche dealers in the Netherlands may be right. It is clear that the engine numbers were different than what our US bulletin says. Please see if you can get them to make you a copy of the service bulletin and then send me a copy."

So, in summary, it appears to me that the actual LUK implementation date should be 5/92, engine serial number 62N07138 (not 62N01738).

Hope this all makes sense!

 

Well, to confuse matters even more.....

I have a survey up on SmartGroups about the DMFs. One of the reasons I created the survey was because of some information I've heard from several sources. What I heard (unconfirmed, by the way) was that because of the low reliability of the original Freudenberg flywheels, Freudenberg may have been forced to make some design modifications and implement much stricter quality control. I wanted to see if the data for the failures reflected this (for example, would the failure rate of a '90 model be higher than it is for a '91 model). The survey is supposed to end at the end of this month and I'm not going to break the data down until then. I'm not even sure if SmartGroups is still running at this point...they've been having a lot of problems lately. I haven't been there today.

Whether Freudenberg generated a new part number for this as yet hypothetically improved flywheel is unknown to me. I'm reasonably certain they did improve their QA, but apparently their changes still weren't up to par. A cursory look at the survey data indicates a relatively high failure rate for the Freudenbergs with failure often occurring around or before 50K miles. SOME Freudenbergs can last a long time....just not very many of them.

CHEERS (I think)

Bill Wagner

 

Dear Randall,
N is model year 1992 not 1993. P is 1993. 62N were 1992 engines. The LUKs in Europe and for the majority of US versions were not installed until the P series of engines, 62Ps starting in August 1992.
The only open issue is now, and I suspect this may be the confusion, is, were the LUKs were fitted into the range of serial numbers listed for the engines to be installed into the 18 series of the RS America, Jan-Jul 1992 build. Option M718. These RSAs all had P series VINs.
I am checking with RSA owners to try and confirm this. If they are not installed this also wipes out currently written explanations of option M718 as well.
Ciao,
Adrian
911C4

 

Hello,

Just for you all, here is a interesting information:
My 964 Carrera 2 is driving aroud with a Freudenberg DMF.
I can't find any sources that it is replaced the past years.
My car is dealer serviced in Italy all the time from day one till 120000km's

May be I start to have a world record..............?????

Just for info.

Arjan

 

Dear Arjan,
Approximately 30,504 964s were built and fitted with the old Freudenberg DMFs. There were two versions. They did try and fix the problem in the 1991 model year. I honestly doubt that 30,000 plus DMFs have been replaced. I do not think we will ever know how many really were but I do not feel that you are the only 964 owner in the world with a high time Freudenberg,
Ciao,
Adrian
911C4

PS: The production figure shown above does not include 1989 C4s, any of the Turbos or the RS, Carrera Cups or RSAs.

 

No argument here ... I just copied verbatim what Bruce A. wrote in his Performance Handbook.

Anyway, at a minimum, it still appears to me that the information in Bruce's book (or its source) is incorrect or has a typo. How else could Ajran's 3/92 car get a 62N05xxx engine if produced prior to May 92 = 62N01738? (Assuming the engine hasn't been replaced with a used unit, of course).

 

O.k.

Watch this............
Now I have original copies of Service bulletins from Porsche.
This means that I have all the Dates and engine numbers on paper!
I recieved this today from a helpfull Porsche man.
Please use this information just for your own.
May be I can get in the future more tech, info from the man.

For anybody who wants this info on e-mail, send me a private e-mail, and I send it to you.

This info is in Dutch, but it says whats coming up next:

Luk used first from 13 May 1992 and engine number 62N07138 for Carrera 2.
Luk used first from 13 May 1992 and engine
number 62N82674 for other cars.
Carrera 4 is using still a Freudenberg dmf because transmission/4 wd reasons.

More information I could not get.

Greetings,
Arjan

 

Hello,
I tried to mail some people the bulletin, but there was may be a virus travveling with it.
I have a Norton Virus scanner updated Jan. 16 2002, but I cam from somewhere else.
Sorry to the people who caught it, I am not the sender!!!!!!
But I feel guilty, sorry again.

Arjan

 

Hi Arjan,

Below is the image you wanted to post - thank you for sending it so others on this Forum can read it! I had to make it a little smaller, so if you have difficulty reading the image - please e-mail either Arjan or I for a larger copy (it is a large file though - so please be aware!)

Hope this helps!

John D.

 

Thanks John!!

Sorry again to everybody who recieved bad E-Mail hanging on my tail.

This is better for everybody who has interest.
As you see it's in Dutch written, but is says that what I told before, May 13 1992 was the dat for using Luk for the first time
in combination with engine number 62N07138 for Carrera 2.
This is Info from a official Porsche dealer.

I hope people can use it.

Have a nice weekend you all!

Arjan Brinkcate, 964 C2 Black