the 3.8 v6 DOHC

 

Then the TSB cited by jsinton doesn't apply since it specifies the problem related only to the tranny mounted with the 3.3 liter V6. jsinton is correct that flushing the transmission with Dexron III at Jiffy Lube has voided your warranty. Worse is you've got to get the Dexron flushed out of the tranny. The seals in the transmission are not formulated to work with Dexron III. Under pressure and heat, the seals will begin to erode and prematurely fail.

 

^^^ There is your problem.

I know this may sound harsh but please stop trying to save money by taking your car to untrained grease monkeys. You are just causing more problems and more repair costs. Please go to a real mechanic that knows what they are doing.