1992 Ply. Voyager Trans. Problem

[adamalltogether]

hello,
I seem to be having problems with my 92 voyager transmission. it has the 3.3L engine and automatic in it. the van has 194000km's on it and has been fairly regularly serviced throughout it's life.

recently i have noticed that it won't leave low gear when driving, and the RPMS read about 3000 when doing about 60km/h, where before they would only read about 1500-2000 and there is no apparent change of gears. the transmission seems to work fine (normal shifting etc.) when the engine is cold, but after it has warmed up there is a slight hesistation and then it drives in low gear, not shifting out as i described above.

does anyone have an idea about what may be happening? i understand that these transmissions are particularly finiky from what i have read about them.
this van has served my well for the past three years that i have owned it, and i am hoping to get another two or three out of it while i finish university.

EDIT: i checked the engine codes using the key metohd and only got code 55, which from what i have read means "no error" or end of codes or something to that effect.

[nipsirc]

I had almost the same problems (hesitations in changing gears, very tight gear shift, etc)but as soon as I had the tranny serviced (changed oil and filter), all went back to normal.

[adamalltogether]

thanks for the reply!
yeah after i checked the error codes and found nothing, i figured that the next best step would be to get the thing into a shop and get the trans fluid and filter changed.
now i just need to scrounge up the cash for that!
or how difficult is it to do the service myself (with a repair manual of course)?