Alright. I have an 01 passport with an automatic transmission. the passport itself runs ok, but the transmission, not so much. From a dead stop, you press on the accelerator, the engine revs, but you don't move. Then the tranny shifts hard into first and off you go. Sometimes it will start out fine, then around 10 mph it feels like the tranny slips out of gear then back in real briefly. Is this a maintenance thing that I can take care of or do I need to take it to a shop and have it rebuilt, or what? I hope you guys have some good news, I could really use it.