Time to finish up this thread. The solution was simple.
- a complete dismount, carefully prising off the ball joints
- Cleaning all the parts
- Bending the last link between motor and linkarms juuust a litle to make a longer circular travelling distance
- grease up all the ball joints, I acctually filled up the ball joint holes with grease before pushing the ball head into its place, squeesing out what is not needed
While assembly on the car I observed the travelling distance on the spindles, simulating the motor running. This to obtain the perfect spot to tighten up the nut on the motor spindle against the connection link. The perfect spot is of course the absolute turning point of the linkarms.
Then mount the wiperarms on the spindles, on drivers side I think it should be approx 55mm from the bottom line of the windshield to the center of the hook-on of the wiperarms. Correct me if I'm wrong ppl.
Well this is the end of this thread for me, I have learned a lot, thanks for all the creative suggestions, hope this could be helpful for others as well. Perhaps not the corect way to do it in a car mechanics eyes, but hey, it worked for me:)