[JWPATE]

Oh no, no, no,
I do not agree. You will not rupture any seal I can think of, in the Tiptronic by overfilling. Pray tell, what seal could rupture as a result of overfill? That is nonsense. Actually, there may have been automatics where that statement may have been correct, but I cannot recall a single one. What you will do in all units, with an overfill situation, is cause a leak to occur. The fluid level will exceed the sealed input and output shaft levels and the particular transmission will drip from other openings, such as shift-linkage holes, not normally sealed against fluid loss.

On your suggestion for filling the Triptronic transmission through the dip-stick hole, well, to be polite, just where do you expect that hole to be? Don, and others on this forum, reasonably expects that you have already read the owners manual, if not the service manual, before asking advice. There is no dip-stick!

With regard to your suggestion that one should “err on the low side”, I would agree with your position, but with some argument. Yes, generally any automatic transmission is better off not to be overfilled, as it leads to leakage. However the Tiptronic in your C2 is no ordinary transmission. Times have changed, and so must we. The fluid in your C2 Porsche automatic transmission requires external cooling. It is, in my personal view, the finest transmission available on any Porsche; but it cannot run without a cooler. Therefore, you are very, very far off-base in thinking that one should “err on the low side” in this case. Have you taken the time to become aware of the ATF cooling radiator? It will be found in your front right fender, and it receives ambient air BEFORE the engine oil cooler? Still want to “err on the low side”? Go ahead, it’s your money.
The Porsche position on this was (and is) to not err at all. To check the transmission level, you will need to accept the necessity for dirty fingers. You must get the car up on a lift or on safe stands, with the engine and all fluids at true operating temp. (15 min drive – minimum). Then:

- remove underbody cladding
- vehicle must be HORIZONTAL
- engine running, at normal temp
- hand brake on
- selector in position “p”
- With Bosche hammer tester 9288 check that the ATF temp is at 80 degrees C. (don’t have a hammer? Probably too bad Charlie! I got one of the last ones. In your case... keep it hot!!)
- With engine running, add fluid until the sight gauge on starboard side of transmission is above min and less than max.

OK, now to Dons note that there was a change (he is always right):
Porsche Note:
The ATF capacity was increased by 0.51. The ATF level therefore rises and the 80C check marks move further up on the oil level tube.
NOW (this is for you), make sure the fluid level is between
Maximum of 15 MM above the 80C mark and, lowest level 3 mm below the mark.
Just as Don suggested (he is never wrong), a slight increase.
Best regards,
James