The wiper system on my 1972 XJ6 Series 1 is a bit of a hodge-podge. The motor is 75967B and this is apparently a S3 model. One wheelbox is original Series 1 C28005 which is no longer available.
I had a broken wheelbox so I substituted a Series 2 one
Here is the problem … the wiper arm sweep. When in park position, both arms sweep 180 degrees, well past the end of the windshield. The arms remain roughly parallel so it appears that the gearing in the S1 vs S2 wheelbox is identical, or very nearly the same. I’ve been told that the sweep of the S1 motor is 120 degrees, and the sweep of the S2 motor is 125 degrees. Since the windscreen is exactly the same in the S1 and S2 (isn’t it??), I assume that either the S1 arms sweep a little bit more, or the S2 wheel has very slightly altered diameter/gearing.
Is this small sweep difference due to different gears in the S1 vs S2 wheelbox?
Is the too big 180 degree sweep using the S3 motor caused by a significant gearing different from the S1 originally in the car?