1988 420SEL 160k Trans popped out of drive on me yesterday (right near Richmond) and then ones I put it back into drive it began working ok. I checked fluid, was ok. Same happened a second time. Then I noticed it is not shifting into the high gear. At 60 mph instead of 2000 rpm I see 3000 and it doesnt shift up. When I put it into neutral and back into drive, all at highway speed, then it goes into the high gear. Does this sound like TransX might cure this or is this bad news?

dave