If there are any signs that fluid has been syphoning out of the valve on top, (which I did have), you might want to check the oil level (only after the transmission is hot (170 degrees I believe it the right temp).
For me, the loss of fluid showed up as pink oil down the curb side of the transmission case. Not a lot but definitely oily and dirty, (I did not have spots on the pavement under the coach). I wiped up the case and after a moderately long drive it remains dry.
When I checked the transmission fluid, it was just a little lower than the halfway point in the crosshatch range on the stick. I didn't add fluid since that is acceptable.
Be sure to use the correct fluid as indicated on the stick.
Gary, Cindy, Reacher (Maine Coon), and Vivian (in spirit only now).
Retired: July 31st, 2013 and loving it.
2011 Coachmen Encounter 37 TZ pulling a 2012 Wrangler Unlimited Sahara. Many upgrades, additions, mods, and changes.