Blair:
Just drain out the trans fluid at room temperature and measure what came out (since you will not get more than 1/2 of the capacity). Then refill with the same amount of new stuff.
Do not locktite the pan screws or you may have issues getting them out next time, if there is a next time.
Tough Tony, great to hear from you. You and Thundershorts have saved my a_ _ so many times.
You know, I think your concept there is perfect with the room temperature. I've always been concentrating on that temp range in the book and never gave ' ambient or room temp' a second thought. Your way would be exactly what the factory fill was - pending no leaks which I would see once under the car. My only fear is on another forum's instructions - the guy made a coment about the factory overfilling his Passat by 1 liter. I can't remember if others noted that too.
I have a Multimeter that also reads temperature off a 'thermometer.' Most thermometers on flexible wire will not survive fluids. What I found on the web won't tell you if their beaded thermo-sensors will work in fluid. Some, will at least , say for ' surface/ air' temp readings - but finding one that is flexiable enough and with a small enough sensor to poke up into the tranny fill hole and survive in a fluid is a different story.
Today I found an outfit that will custom make what I want for a $5 upcharge from the not so hot web sites I found. $20 total. Heck Craftsman wants $15 for a lessor sensor not made for fluid. A beaded thermometer made from teflon wire able to survive in fluid up to 350F and just a 1/2" stainless sensor at the end of the thin cable. Flexible and skinny enough to shove up the hole and drop down into the ATF pan - even with the hook that I use to fill the ATF in that same space. We even toyed with me sending him a drain plug and him attaching a temp prob though it so I could just hook up my Multimeter to my drian plug . Yeah, I know - we were getting a little nuts on that one - but this guy was serious. I killed the drain plug with temp probe.
I told him for some unknown reason VW either wants me to replace the drain plug with every fill - or - they just simply refuse to sell the sealing washer to that drian plug without selling the drain plug & washer as one unit for over $11. I told him that crazy arrangment of not being able to buy just the gasket for .75 cents makes me think it might work like a stretch bolt, but I would not bet the ranch on it having any stretch tension to keep it from vibrating out. Probably some glitch in VW parts ordering. I also didn't want to risk his sealed prob though the drian plug developing a leak.
If anyone cares : that outfit was
W. H. Cooke & Co., Inc.
6868 York Road - P. O. Box 893
Hanover, PA 17331-0893
He also had adapters. Many thermo wires have a ' mini K' plug at the end. If you have an older Multimeter - it might only accept banana plugs. No problem. He's got the " mini-K to banana plug' adapter too.
After trying it out on my tranny, I'll shove the probe up my home's AC vent. Either this hot spell in CT is worse than they say or my upstair's AC has a leak and is not putting out the same temp to what it did some years ago at these same outside temperatures.
Blair