2002 chrysler minivan 60k, bump shift transmission

2002 voyager 60k, going 50-70 transmission

drops into passing gear then back up. sometimes 3-4 times .last time got down to 25 mph and was continually shifting. stopped and got mechanic , drove it, did not do it again. on way home, started to do it, I gunned it to 90 and stopped doing it and was o.k. going home. computer says transmission in perfect shape. no engine light comes on. selenoid pak replaced, serviced transmission at chrysler dealership. HELP

Was this the first time the transmission was serviced? The general consensus is that automatic transmissions should have their fluid changed every 30k miles.

If this started after the fluid change then you can have the dealer flush the computer and that should fix it. Otherwise it should go away after a 1000 miles or so. If this is not related to fluid change then totally different story.

Sounds like one possibility is a failing throttle position sensor - or some aspect of its circuit.

Intermittent problems are just really hard to track down. You best bet is probably to have someone drive it around while on a scanner to see if data from one of these events can be logged.