gearbox lookup...? 915702 7339-12

whiteSC59 · 06:16 AM

I think this is an early 915 gearbox but can anyone tell me where to research any tranny using the number from bottom of the case. id like to know if you can tell by looking at the numbers if something might be lim slip or ?? heres the numbers and thanks in advance...915702 7339-12.

just realized it may be 915/02

Grady Clay · 10-21-2009, 07:07 AM

7339x12
7 = Transmission for 6-cylinder engine
3 = Transmission type 5-speed 915/02
3 = Model year 1973
9x12 = Sequential Number. (very late)

915/02 = Transmission without oil pump and ground gears.

1st = 11:35
2nd = 18:33
3rd = 23:29
4th = 26:25
5th = 29:22
R&P = 7:31

This has a mechanical speedometer and all magnesium castings. The transmission axle flanges fit the 108 mm CV joints with four M10 bolts and two 10 mm pins. This probably has the ‘install from inside’ input shaft seal.

Best,
Grady

whiteSC59 · 10-21-2009, 07:58 AM

thanks grady.
im not knoledgable about these gearboxes so some of what your saying about input shaft seal and flanges, cv joints ect doesnt mean anything to me cause i dont know the difference but trying to learn. did these come in lim slip? is this a desireable gearbox and better than one from an sc?? ive just heard things about the 7:31 r&p...thanks again for your generosity of knoledge.

Grady Clay · 10-21-2009, 08:24 AM

whiteSC59,

What is your intended use?

The 915 transmission was delivered in 911s from ’72 through ’86 with the last production types being 915/72 (RoW) and 915/73 (USA/JapanM298).

Needless to say there were ‘improvements’ during all these years. In general these ‘improvements’ were for the better. Like any sequence, you can ‘pick-‘n-choose’ among all the transmissions and component parts and build a transmission that is better than anything Porsche originally delivered. This is the wonderful part of ‘hindsight’.

There is a lot of information available here. Use the search function. Be patient, there is a lot of information. I'll be glad to help with details.

Best,
Grady

Mark Henry · 10-22-2009, 10:07 AM

Is there a data base on these numbers?

I've also some amazing production numbers on the engines, but even they are meaningless to me without some kind of code key.

is there one? if not it would be a nice tech reference

Grady Clay · 10:44 AM

Mark,

Unfortunately there is not one, single reliable source.

I have my collection of Factory ‘Spec Books’, Factory Workshop Manuals, ‘Service Info’ booklets and more. Less reliable are the commercial books; Red Book, Data Book and more. The new The Porsche Book, The Complete History of Types and Models by Jurgen Barth seems to be the best of all commercial books.

Porsche New & Recent Titles Books

There are many websites, some of dubious quality.

When looking up a specific number, it is useful to investigate all the possible sources. Be careful as some mis-information is repeated by one source looking at another. Much of this information Porsche AG has lost.

Best,
Grady