Flashforge Creator Pro - replacing plastic pulleys

My FFCP has has been a workhorse for the last year and printed more than 2200 hours without much problems, thats almost 8.5 kilometer of filament.

So yesterday i wanted to give my printer a good maintanance and took it apart, in the process i wanted to change the plastic pulleys. After putting it together again at first site this worked out great as i didn't had to change any of the original adapters, now when starting a new print the size of the printouts don't match anymore. After some inve