I have 00 venture which I think has similar problem to many other people, the harsh shifting i have happened always when there is a "whining sound" or "humming" comming" - I am not sure how to name that sound-, if I stop and shift to "P" Or "N" prssing on the accelrator will show up this sound. some times if I stop for a minute it will go, now days it will go for a while then comes back
any help is apperciated