Hi, I just bought a used 1998 C280 Sports. The car has 99K miles. After driving it for about 200 miles, i noticed that whenever the car would shift from 3rd to 4th gear, it does a hard shift. Down shifting does not seem to be an issue. However, the hard shift (or jerk shifting) from 3rd to 4th is not consistent. I now have it scheduled to get into a MB mechanic to take it for a test drive and diagnose the problem. BUT, after driving for about 30 miles, it does not upshift anymore, and i've got a couple more days to go before my mechanic appointment.

Anyone has any idea what the problem might be and/or what the mechanic will come back with as a diagnosis?

Thanks so much for any help!