We own a 2007 Chrysler Pacufica. We had a transmission flush done at a Chrysler dealer around 70k miles everything went goo . Then a few months later it started shifting rough. They say they found metal shavings in the transmission. And the oil cooler is plugged. How does it get pugged if its after the filter. And is it normal to be charged for over 6 gallons of oil for a flush? Shows five 5 liter jugs used and one 1 quart jug used on the invoice.