Is "hot" at ambient temp (+/-100F) sitting on the floor in your garage, or are you heating the stored fluid to equal actual 80C operating temp and then looking for the change in volume?

Going from 60F to 100F would be a minimal % increase temp and corresponding expansion.

If you are going from 60F to 80C that's an ~300% increase in temp.

To actually see the diff in expansion you'd probably need a sealed container with a small diameter clear tube that the fluid was forced to expand into. That would approximate what is happening inside your trans when fluid is measured cold vs hot.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)