OT marking on a 3BG Passat 1.9TDI AVF with TT5 automatic transmission?

Hi,

Can someone tell me where, regarding the above? Where can I find the 'OT' marking on the vehicle, specifically in the transmission area?
Does it actually work in the vending machine? I don't have a flywheel, just the starter ring gear.


Background:
'I recently replaced the timing chain and now I'd like to re-check and possibly fine-tune the timing, as it runs great at low RPMs like before, but it seems to struggle a bit at higher RPMs on the highway (referring to the early/late timing effect, as there are already a few threads on this topic).'

Since I don't want to disassemble half the front end again just to install the KW stop, I want to try marking the transmission first.



Okay, my charging voltage is a bit too high (the gauge reads slightly above the recommended range when the engine is cold, roughly in the middle of the metal tab at the end).
Does that make any sense?


Thank you in advance.

does anyone have a plan?