Benzoboy, thanks for the information. Based on your input as well as the results of some additional research, I bit the bullet today and made the drive to the Mercedes dealer. The parts lady confirmed what you'd said, citing the fact that one could use Dextron ATF in older MBs ( a good friend has a '78 450SL and he does this), but that a newer one such as mine (19 years old is newer?) needed the special MB fluid. I put it in and, Presto! problem solved.