I have a 04 auto TL and when it gets up close to shifting to 3rd there is a bad vibration before it shifts. But when i put it in slap shift mode it doesnt do it. Anybody had this happen or have any ideas as to what it could be? I know it needs a tranny flush but i dont wana spend $200 bucks if its gona need tranny work anyway

 

Check your side engine mount. DO NOT DO THE TRANNY FLUSH. Only do the drain and fill 3x3. Do your research on that if you need more details.

 

Do your pressure switches and. 3x3 drain and fill