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Posted by: Gustl May 7 2009, 11:05 AM

o.k. folks, here's my question:

could an original 914-6 transmission with the factory option M220 (limited slip differential) be identified by the transmission number ???

I know the difference at the 914-4 transmission:
HAxxxxx ... 5 speed standard
HBxxxxx ... 5 speed LSD

any input is highly appreceated

Gustl

Posted by: 9146986 May 9 2009, 12:43 PM

I don't know if it applies to 6's, but 4's with LSD had an aluminum tag on one of the side cover nuts.

Posted by: kwales May 10 2009, 09:33 AM

According to the factory parts manual, the answer is maybe....

1. A 914-6 tranny has a part number of 914.300.012.03 with the -6 gear ratios inside. All trannys for a 914-6 would be drawn from that supply during a factory build. For some reason, the parts book has a column called denomination which has another number for a 914-6 "transmission complete" of 914.300/01

2. The LSD was an option. The parts book has a series of columns labeled "Stuck pro Typ" and it says that the LSD was for "Alle" except the sportomatic.

3. To the left of the "Stuck pro Typ" columns is a column called "Symbol" and under that collumn is the symbol "M". That must be how the factory differentiated "alle" transmissions with the LSD. Now why the Symbol "M" is used by the factory to identify the LSD, and why the factory used the stamped HBxxxxx designation for the change is a mystery.

Has anyone checked a factory built LSD transmission for the symbol "M"????

Ken

Posted by: davep May 10 2009, 10:13 AM

At least by the 1980's the 915 transmissions had a "12" between the transmission type # and the serial # to indicate an LSD. Still trying to find the correct answer for you.

Posted by: Gustl May 10 2009, 11:30 AM

thanks Ken

this would lead me to the question - is there anybody with a factory original 914-6 LSD transmission (M220) ??

if so, could we get photos of the transmission number - or / and this symbol "M"
would also like to where this symbol "M" is located?

sounds interesting ...

Posted by: kwales May 12 2009, 12:21 PM

What's on the aluminum tag????

The symbol "M"????

Ken

Posted by: HaraldD May 13 2009, 12:09 PM

Hi!
Here is one of a original 914-6 Tranny with LSD (from the Factory)
Harald

Posted by: Gustl May 13 2009, 02:38 PM

thanks Harald
this is exactly what I'm looking for

would be nice if there are more photos to show that this isn't a one off

Gustl

Posted by: davep May 18 2009, 06:23 PM

Since the later 911 transmissions used a 12 to designate an LSD, the practice earlier must have been to use the "10".

Posted by: Richard Casto May 18 2009, 07:15 PM

I have put together a wiki page about the 914 transmission. It is located here...

http://www.roadglue.com/wiki/index.php?title=914_transmission

As with any wiki, please feel free to jump in an contribute. Particularly those of you who have years of special 914 knowledge hidden away in your brain!

With help from Harald and Gustl, I have added a number of photos of serial numbers. I also have some additional photos that Gustl has sent that I still need to add to the article.

Posted by: Gustl May 18 2009, 11:22 PM

from what I found out yet, I believe that the "10" indicates the 80/20 LSD (like used at the 914) while the "12" indicates the later used 60/40 LSD tranny

Gustl

Posted by: davep May 21 2009, 09:12 AM

Ah, excellent information. I wonder what '11' would represent then; something intermediate perhaps?

Posted by: Gustl May 21 2009, 03:13 PM

the logical consequence would be 70/30 ... but I didn't find anything about an odd number
in fact, I hardly find anything at all ...
I even don't know if Porsche ever used a 70/30 LSD at all

Posted by: Tom_T May 26 2009, 07:06 PM

According to the charts at the web link above, the /11 & /12 on 914-4 tranny's refers to the tail or side shift configuration respectively - although that info may not be completely correct -
unless the basic case was interchangeable for tail or side shifter setups?

I say this because my mechanic - Hans of Hans Imports - had used a "used replacement case" to rebuild my early 73 2L side-shifter back in 12/83, when it's original case was too worn-out inside to use - see the pic of my current used case # below:

"HA" transaxle # used in rebuild for my 1973 914-2.0 (VIN 4732901954 & Engine GA000424 & still matching nos. from 9/72 build date):




Sorry to add to the confusion here, as I was only drawn to this post to figure out what LSD stood for, after seeing it in the parts forum!

...but hopefully it adds to the forum, & feel free to use it on the tranny article - but please leave off my VIN & Engine numbers there!