I have a 1990 760 turbo and I believe the transmission fluid is low. I don't have an owner's and/or service manual for the car. I checked the level while the car was up to temperature and running in park however the stick had two different reading levels on either side whether the car needed more fluid or not: one at 40-degree C and one at 90-degree C. Not having a manual, I don't which reading to refer to. I would think that since the car was at running temperature that it would the 90-degree C reading but can someone please advise on this. I've been searching the Internet for an answer to this seemingly simple question to no avail. Thanks.

The 40 degrees is for checking it cold. The 90 degrees is for checking it hot.

Thank you very much for replying, I truly appreciate it. That would be logical answer that one would surmise, except why woud Volvo assume that when your engine is cold that the temperature reading would be 40 degrees (which was the root of my confusion)?

Im not sure why they assumed that but the fluid does expand quite a bit.