Hi Pierre,
So sorry to hear about you sis-in-law parents.
Its kinda bad in Indonesia, at approx 80K ish still actively infected with C19.
USA is much worse at 29 million actively infected, but USA testing is 666K per 1 million population, while Indonesia is only at 23K is per 1 million population.
Anyway.... let's discuss mechanical

I got a few photos from EBay UK, so for right hand drive car.


Basically we are to loosen the bolt where the red arrow ( or #50 bolt below ) I marked is.... correct ?
Then we push down or pull up the entire wiper assy and the small L bracket item #20 below is what made the adjustment up/down possible.





What I can't confirm yet is, the definition of NEGATIVE and POSITIVE angle as per document.
I would guess LEFT is the NEGATIVE angle, simply because we right hander tends to think RIGHT is GOOD = POSITIVE





Below is what Sangyong cars WIS looks like on wiper adjustment, but its the BEND-THE-WIPER-ARM method .. LOL
http://neon.lofis.net/SsangYong/Serv...onB1701005.pdf

A French company selling digital version of the angle meter/protractor : https://www.measure-control.com/prot...931x-A_a7.html


Here is a DIY angle meter by someone



I will pursue this adjustment Jan 2021. In 36 hours I will be driving to Bali 1,250KM distance, with 2 days stop over at a East Java small holiday city with 1,000 meter altitude which can give me 23 Celcius daytime weather...YEAH !!!
23C is good enough for me a 32-35C city dweller.

Hence I was looking for a fast fix on the wiper skipping issue.
Indeed, I would not ignore this fun-of-an-adjustment ... Jan 2021 I get you Wiper System !!

Have a good Christmas and a Happy New Year to you and family and all of the MB Gang in this forum.

 

Yes it was tough for her, one sister here in Kalifornia also, but one in Jakarta that went to take care of final arrangements, they were 86 and 87, with other health issues, so long full lives.

wow, that wiper system is completely backwards! but yes, the bolt in red moves the system app or down, mine was only off by a degree or so, so I moved it "up" a bit then in spec, so I moved on after boatload of parts on the bench, but I figured I have to start at the beginning.

I interpreted the angle gauge as left negative, right positive {political reference LOLTalking} nice factory tool though, I used a machinists angle gauge, carpenter's Speed Square and duct tape! rudimentary but functional, Adjusting the wiper aasembly did not bring the wiper arms into spec, I had to manually move them from the bottom test position to the top test position then used a new fangled self-adjusting "vice grip" with plastic pads installed for bending the wiper arms, these are nice I suppose, but not even close to replacing real "vice grips" which have sharp teeth lock tighter and can be hit with a hammer if necessary! As I mentioned just went back and forth measuring angle tweaking wiper arm until I got top and bottom position in spec, None of the four [positions] were at the "mean" or center of specification, only way I got them in spec was bottom to the low end and top to the high or positive. Love that electronic angle meter, would have been easier on my old eyes!

Anyway, I'm glad your OK and you'll be getting out of the city heat for awhile and less congestion/people and Selamat Natal and Selamat Tahun Baru to you and yours!

Damn, now I'm wondering if I would of fussed around with the wiper assembly angle a bit more, I wouldn't have had to bend the arms. S***

 

UPDATE TIME .............. Hella CleanTech Wiper Blades

It seems so obvious now that I will need the wiper angle of incident adjustment, at the least for the driver side ( right side, mine is right hand drive ).
Good thing I did the wiper blade change. It was raining a lot Jakarta-Bali-Jakarta road trip.

No skipping, but the right side wiper ( driver ) eventually developed 2 unique water trace line if rain is light drizzle. The line #2 is not wiper issue, it is insect fat/protein as stain on the windshield , line #1 and line #3 is the wiper blade issue.
Line #3 is not a line per-se, it is more like wiper blade did not make good contact to glass and is not a thin line but like a spread of 10-15mm watery surface.
This condition is after some hours of operation.... when under 1 hour of use, it was fine. I think the "wrong" angle of incidence eventually caused the wiper blade , at certain blade areas to not have a good contact with the windshield.


Since left and right side wiper are the same, if I swap them, then the right side wiper behave well for left side use and the left side wiper will have those lines eventually when being used on the right side.
So this is surely related to angle on incidence of the wiper stalk/arm.

Good thing if the rain is heavy, I only get 1 obvious water line........


End of Wiper report....