All,
I know for a fact that a TSB has been issues on the MTX-75 from Ford. The TSB instructs to use the same fluid "cocktail" mentioned on this thread. As a matter of fact, the TSB specificaly recommends using Mobil-1 synthetic ATF.
So far with 11.7k miles on mine, shifting has never been a problem. However, I do get a real heavy clutch pedal after driving 10-15 miles at highways speeds without shifting (but not always). This problems is quite elusive to duplicate.
Later,
David