I have a 98 Passport that just rolled over 150,000 today on the way home from work. For the past couple of weeks, it slips when accelarating moderately from a stop (by slips, I mean when accelerating, it jerks as it it's slipping, then catching realy quick around 4-8 times before catching and moving on to the next gear). If I go REAL easy on it, it tends to no slip in first or in between first and second. The transmission was flushed 4000 miles ago when I bought it. It also tends to shift abruptly sometimes and can take a while to lock into first after backing up. I was going to check the dipstick to make sure the ATF wasn't low, but they don't have one. I guess there's two plugs you ahave to remove, and fill one until the other starts to pout ATF out. Thoughts or suggestions on what could be going on, or what I can do?