decoding my turbo gearbox number

[klasikcis]

Having owned my turbo for 6 years decided it's time to change the gearbox oil. In the process decided to see if it had a legible gearbox number. Although it has the usual dents and grazes most numbers are legible. The only numbers that are clear are 779 space 0158. looks to have 2 or 3 smaller numbers or even a numeric and a number preceding these numbers but appears to be a separate stamping, seem to be maybe the remainder of 930 34 which i believe is gearbox type. Guessing the first 7 could be 6cyl second 7 gearbox type and the 9 for year leaving the last 4 as sequential numbers???
For the record Australian delivered matching numbers vin and engine built September 1978 delivered 24th November 1978. Sold by John Newell NSW.
Also what gearbox oil is recommended, the articles I have looked at recommend Swepo 201 for both LSD and normal diffs and it is an oil which I am not familiar with and as yet I haven't tried to source. The car is lucky to see 1,000 kms annually.

[Kane k]

Swepco can be obtained from

Process Chemicas and oils
1048 Glenhuntly Rd
Caulfield Sth Vic 3162

3.785 litre $229 well that was the price as of 5.06.18, probably more now, with the dollar so bad.

Is it worth that money, undecided ?

Dont have the gearbox in car yet to answer. If you read the hype, the answer seems to be yes. But it is big bucks for not much oil.

Maybe someone can chime in with its validity.

[mrar]

Here's one I prepared earlier...
Had it on file.
Will check later on the code but I recon your close, Turbo is usually 7 maybe 79 for year then four serial #'s.

IMG_1374.JPG

[klasikcis]

Thanks Sean / Kane. Would be great to see what oil most people are using. Swepco seems a good option for track/competition use or even worn boxes but I am not sure that I am going to drive mine in anger. At least not when Jan is in the car!! Love to find the interpretation on the first three numerics.

[HughH]

gearbox codes (based of earlier years pattern so not certain of the exact meaning of all of numbers)
7 Transmission for 6 cylinder engine
7 transmission type (I know that it is a 930/34 four speed so my guess is that is what 7 represented in that year - earlier it was 5 speed 915)
9 is the model year and given that is was built in Sept 78 that would be 1979 model year
xxxx sequential number so yours looks like 0158 and therefore no missing numbers even if a space (which is likely to be created by the machine stamping the numbers as the last 4 would change each stamping

[mrar]

Beat me to it Hugh.
Yep the second 7 denotes 930
and if there is a 11 or 12 between the gbox type and the 77 it means lsd fitted.

[klasikcis]

Thx Hugh & Sean at least I now know that I can go back to Porsche Cars Australia and have the vehicle details sheet updated to include gearbox code which I am now 95% certain is as originally fitted. It was not supplied with an LSD according to the listed options and I can confirm that the gearbox in it is non LSD and as such does not have an 11/12 in the code.
Last request is what oil is a suitable gear oil to use in the gearbox which is in excellent condition. Nev

[klasikcis]

Good news, Porsche Cars Australia have confirmed the gearbox number as the factory original.