This is dangerous to bring up since you say there is no problem when at the lower level of fluid, but there is a Throttle Valve Cable that will influnce your shift points, but it will not influence just one gear, but the whole spectrum of shift points. So if you got 4th to shift early, chance are, 1st and 2nd might seem to abrubt to you but my 300-e came off the show room wrong. A good mechanic got my Auto Tranny to shift in manner that I would if it were a manual. If you do play with it, mark where you started from and the adjustments are small in normal circumstances.

Sorry about this post, I clicked the 'new topic' instead of the reply. Not enough coffee this morning. This was suppose to be a reply to the guy with the funny shifting 300-E