1998 Grand Voyager 3.3 with 125K miles. Routine service has been done (fluid/filter changes at roughly 50k and 100k). The wife reports that intermittently the van will, from a stop sign or red light, rev and then eventually drop into gear harshly (like textbook low fluid level). Of course it will never do this for me, but I don't think she's crazy (on this point at least...). I have checked the fluid level multiple times ("don't overfill! between bottom holes warm, between top holes hot. idle in Park. don't overfill!") and it is NOT low on fluid. The fluid is not horribly dark or smelly. Looks like 25K old ATF to me (which it is).

I know enough not to expect a fluid change to help at this point (especially if the friction material suspended in the ATF is the only thing keeping this trans from complete failure).

Emotionally, I want to believe that there's a secret $20 externally-mounted flanged niblick control valve that is to blame.

Intellectually, I know that I have a transmission on the way out, and it should be rebuilt.

Is there something I'm missing here (or a secret flanged niblick valve)?