I have a 99 plymouth voyager se 3.3 I just bought it & upon driving it awhile I began to notice that it shifts hard into 4th from 3rd depending on my aceleration & sometimes slams down into 1st from 2nd when coming to a stop i've also noticed then when I come to a complete stop the speedo is still @ 10-15 mph then goes to zero there is a short delay the speedo seems to not match my speed. There is a whine but idk what it is the whine is there in & out of gear

SOURCE: 96 plymouth voyager no shift

you say the fluid looks good... that's great.
now next time your out drive for about ten good minuetes long enough for the transmission to get nice and warm and then pull over to nice level ground and with the vehicle in park check the fluid again. it's kind of hard to read because it always has a lot of bubbles on it and stuff. but it may be low on fluid.. good-luck ray

SOURCE: Trans Locks In 2nd Gear

Your transmision shift selonoid is bad. Had same problem on a '98, changed the shift selonoid and works good now. It is located on the front of the transmision under the fluid lines. The part is about $150.00.

SOURCE: transmission won't shift to 2nd and 3rd gears goes from 1st to 4th.

Doesn't sound like a simple fix. I would suggest having it serviced.

SOURCE: Voyager transmission problem

Sounds like you need a solenoid pack to start, and possibly a service. If the tranny is not slipping, the solenoid pack is stuck and not tell it to shift up. Could possibly be a TCM, but not as likely.

SOURCE: 1997 ODYSSEY AUTO TRANS SHIFTS HARD BETWEEN 1st & 2nd, 2nd & 3rd

It has nothing to do with the transmission, it's your engine mount thats bad.