I purchased a 2010 Sebing Convertible last year from the oringinal owner with 85k miles. We are now around 92k miles. In the past month, The sebring will periodically jerk and fail shift down correctly with RPMs remaining high. It does it from hot or cold. It will be normal and then all of the sudden bam and rpms are high away and motors is louder than normal. I already had it at one shop for 2 days and they couldn't figure it out. There are no codes present except for the gap cap which has been replaced and won't stay off. Any ideas or suggestions?

 

I would suggest dropping the transmission pan and replacing the filter. Check the pan for metal chunks. Fuzz on the magnet is expected. Refill with ATF+4 only; Walmart supertech is licensed and the best price I have found. Plan on 5-6 quarts.

Sometimes a bit of fresh atf+4 will do wonders for these trans