The wiper on my '87 300TD is always in the 11 o'clock position when turned off (viewed from behind the steering wheel), i.e. it sits further up the windshield when off than it should.

The wiper works well when needed and wipes all the way to the bottom of the windshield on both sides, but always returns to the 11 position when off or resting between intervals.

Would this indicate that it is installed incorrectly? Or is there an adjustment that can be made while it is installed to move it back a few inches closer to the 9 o'clock position?