Perhaps I am wrong, but both of these screws are important for adjustment, please correct me if I am wrong.
I just went through it a few weeks ago. Of course I marked all the shafts and levers locations vs. each other, etc. before disassmbling. When I put it all back together, it did not work. The wipers started from parking in the opposite way than they should for a short moment, then they were going to the direction where they were supposed to go. Trying to adjust lever length did not help.
I started looking at it and I figured:
- for the wipers to start in the right direction (without moving back a bit and then forward), the upper end of the motor shaft lever (the end connected to push rod) has to be in its highest (TDC) point when engine is in park; I got there by unscrewing this nut marked previously on Fig. 5, taking off the lever and screwing it back on
- then by experiment I figured that the length of the lever (adjusted by the second screw you are talking about) is for wipers travel adjustment
They are both for adjustments, actually, I think.
Again, please correct me if this is wrong, but this is how I got my wipers work right...
