Have a 85 300D with 157K. Am interested in replacing transmission fluid. Two questions: can/should I do a transmission flush (like BG, etc) or just change it. Been told by one shop that they are reticent to flush an old transmission. But I listen to Pat Goss every weekend and he really talks up the flushes. Second question -- can/shoud I use synthetic ATF when I change? IF so, what about Mobil 1, or Castrol? Open to any ideas, just want to do what is best.

bob
85 300D, 157K