Hmmm, a more in-depth divulgence of tranny slippage? I recently replaced my tranny filter with a WIX filter from OReilly...they have always been great filters for all other vehicles. It was a direct drop in. I put in new tranny fluid and it seemed like it didnt take the 6 quarts they recommended...it was closer to 4 and it still says Im over...but no seals have blown yet. Anyways, that aside...the slippage usually happened between 3 and 4. It was minor slippage but enough to get irritated and question your investment. The new filter seems to help but when the tranny is warm and the car is in traffic, I get that very slight slip between 3 and 4...anybody? Ooooh, another question...what is this vacuum that I should be looking at...and how?