Problem with power shift

[WordSmith]

Ford Mondeo 2.0 TDCi Powershift, 2010 model year

The gearbox fluid was changed at 117,000 kilometres, and the current mileage is 125,000 kilometres.

Every time I shift from second to first gear or during an upshift, I hear clunking and jerking sounds. Light acceleration is accompanied by a metallic noise, resembling vibrating springs, between 1,500 and 2,500 rpm. With the exception of a few slips, the car is reasonably stable on the highway; on the 500 km return from Spain, I had six 2-second slips. The vehicle stutters between 1,000 and 2,500 rpm, as if the computer is desperately trying to find traction in every gear (even manual mode).

Are any suggestions out there?