where are the Nrs ?

Can anyone tell me where I can find the O1e,O16 etc designation on an audi gearbox? Thanks DJ
The gearbox identification is located on the starboard side of the tranny on the side of the blackened section of the unit. you should find a number like 016301211C. This number will vary depending on the model of the gearbox.

On the top forward area you should find a designator like AAZ or APU. There many of these codes that tell you what the gears and final ratio of the box are. You can search the forum threads for a listing of the code you find on your box.
As Tom says, on the top of the bellhousing at the front you'll see the particular ratio designation stamped into the metal.