[THE NEW GUY]

Ok friends. I've pass trought that when I just bouth the car.
I decided to go on my ouw risk and disassembly the whole mechanism. I found that the drive arm from the motor assembly have two possitions: short and long. This mechanism is pressed hydraulically and seizes with time. In Winter side, the motor turns one way only and the mechanism stays in the shorter porsition. In the sumer side, the motor turns one way in ordinary wipes but turns the contrary way on the last wipe, so the drive arm switches from short position to the longer, making the blade arm to travel more distance to reach the sumer rest point.
In a few words, you have to disassembly the drive arm and lossen the seize on it so it can switch positions automatically, with only the resistance of the blades friction to the windshield, when the motor changes the rotation.
Be extremelly carefull: this mechanism is very complicated to understand. if you miss the original position of any of the parts inside, you may not be able to reassembly it and will have to get a new assembly from subaru. You can unmount it and send it to me to fix it. I'll send it back in perfect operative conditions and ready to be replaced. I live in Montreal.