Michael Benno

Does someone have the document that breaks down the series numbers on the transaxle for the different model years. It shows if the models was manual or automatic, geographic region (USA, ROW, etc) and then offers the breakdown on the limited slip or standard differential.

I remember seeing a Porsche resource document not too long ago, but now I cannot find it. It had very detailed information. I would like to help a friend identify if his gearbox has a limited slip. Here is his trans serial code for his 1982 Euro model: G28/05 11C 0685

I did a little research and found this resource: https://www.928gt.com/t-928trans.aspx. But it doesn't give details on the limited slip.

Any help is appreciated.

Ducman82

Do a vin decode and see if it has the 220 option (LSD)

Michael Benno

Good idea, however, I'm not sure if the tranny is original of if it has been replaced.

ammonman

Support the rear of the car on stands, release the parking brake and turn one wheel by hand. If the opposite wheel rotates the same direction the differential is a limited slip unit. If the opposite wheel rotates the other direction the differential is a standard open type.

Mike

GregBBRD

The 2 numbers after the type identification (G28/05...which is a USA model transmission) tells if it has a limited slip or not.

"11" is a non-limited slip.
"12" is a limited slip.

The "C" designates the year.

The "0685" is the serial number.

All of this information is in the Workshop Manual or a pocket spec book.

Rob Edwards

A28 transmission operation book, page 3:



80-84 specs book with similar info, plus some S/N ranges:

Michael Benno

Thanks everyone for the info. I feel a little like a knucklehead for not remembering to look in the tech spec. Thanks again!