The TSM starts out with checking fluid and linkages first, then it goes on to pressure tests and disassembling the governor. In passing it says to check the filter and the torque on internal components, and toward the end of diagnostic procedures it talks about adjusting the front band, which is the one done without dropping the pan.
If I were doing it in the driveway, I'd do a filter/fluid change and go ahead and adjust the front band. You may want to adjust the rear band while the pan is off since you can access it. It just takes a torque wrench.
Check the torque on the valve body too while you're in there, you may just have a loose bolt.