727 trans problem

Sounds like your gonna have to drop the pan to check things out. Check the rear band adjustment first. You didn't mention what year trans. you have but most are backed off 2 turns after you torque it to 72 inch lbs. If the band adjustment was close it is possible the problem is in the rear servo or linkage. If no problem is found with any of these items the problem could even be in the front clutch. Either way first step is to drop the pan and inspect things. Good luck.