Thanks for the replies. I find it odd that the Chilton or Hayes books don't mention these at at all in reference to transmission fluid change. So, I have no procedures in those books to follow to empty these fluid cavities. I'll search this site for diagrams, etc. I really don't know where the torque converter and cooler are located and how to access the bolt to drain them.

Also, I wonder if when I used to take my car in for a transmission change if they go to the bother of emptying out and changing the torque converter and cooler fluids.

In any case, my regular tranmission fluid change seems to have improved my '84 300 SD's downshifting in particular, but all of the shifts are smoother. I also found and replaced a very decomposed rubber vacuum tube feeding the transmission, which also may have helped.