Started by replacing the rubber gasket at front door and the shock absorbers. they seem to be subject to wear and tear so while having the machine disasembled i tought it's a good idea to take care of them.
but that did not fix the main problem, the water leak. it did however helped a lot with the vibrations. the machine runs a lot smoother.
the old springs did not show any kind of damage or anomalies, but i decided to change them anyway, beeing the last thing that can influence the position of the drum. and it worked.
thanks to the howto videos the job is quite easy.