I own a 2004 Endeavor LS with AWD with 78,000 miles. I carefully maintain the car. Because I sometimes tow, I flush the tranny every 15,000 miles. The color of the fluid says the mechanic is bright pinkish red. I wisely tow below the 3500# limits. Lately, I have noticed a shutter in the tranny at very low speeds. This happens intermitenly and goes away at higher RPM's. This is happening while not towing. I read in the forum about a computer for the tranny. Is this an issue where I may have to reprogram a computer on the tranny or is this a pump problem or something else. Like I said there is absolutely no dark color in the fluid nor does it have a burnt smell. Please advise.