350CDI 7G gearbox

[Paddcomp]

My CLS has started with poor gear changes. Setting off in 2nd and changing to 3rd comes with a noticeable thud. This is normal acceleration using 1500-2000 rpm gearbox in C mode.
Anyone else experienced this problem, I'm thinking I should return to the dealer but would like to know more info before discussing.

 

[SimonsMerc]

Go back to the dealer. Changes should be sublime.