Fluid is changed
My after market converter had no drain plug it turns out so I let it drain for 2 days, about 9 quarts collected, then changed the filter reinstalled the pan and ran about 3 extra gallons of fluid through the transmission by unhooking the cooler return line at the transmission, starting the engine in neutral and running out into a milk jug about 2 quarts and shut the engine off so as not to run the pump dry. Another quart would be draining out of the cooler while I refilled through the dipstick tube. Repeated this process several times until fluid basically looked like hydraulic fluid although it still looked a little pink when I quit. Used about 8. 5 gallons of new fluid. I recall reading somewhere that some people run about 3 quarts of regualar fluid with the hydraulic anyway. I wish I knew more about this.
As it is, I will drive a few miles and flush a bit more through the system.
It was a 75 degree day as I did all this and when I took it for a test drive I could not tell any difference in shifting. I only drove about three miles and returned home to get the fluid level adjusted.
I will be driving about 50 miles tomorrow in city traffic but will not be towing for another week. I will post those experiences soon.
BTW --- any thoughts on a well maintained 258000 mile transmission remaining life.