If you can't find a good tech, I would head for the closest Autozone and have them check for error codes with a scanner. It's free. Could be the transmission itself but, most transmission problems are created by sensors and their circuits feeding the transmission bad information. Hopefully a code will show up to reveal the problem.
If nothing shows up, the first step in any transmission problem is to change the fluid and filter and inspect for metal particles in the fluid. Use nothing but ATF-3 or 4 fluid. Keep in mind when you drop the pan you're only changing about 1/3rd of the fluid. The rest is trapped in the torque converter. You'll either have to change it several times, driving it around beween changes (pump it out the dipstick with a pump) or disconnect the cooler lines and pump it out there. Inspect all sensors and associated wiring/connections for security/corrosion/worn areas.
If the worst happens, make sure they change the torque converter along with the tranny and flush the cooler. Particles can get trapped there and trash your new transmission.
Last edited by RIP; 09-03-2007 at 03:10 PM.
******** We took the time to answer your post. Please give us some time and post the fix. You'll help hundreds. ********
**** Follow all prescribed safety procedures before attempting any repairs. If in doubt, refer to a maintenance manual. ****
96 Gr Caravan LE 3.8, 214K miles
07 Fusion / 06 RAV 4 / 06 Accord