The results so far.. a bit of a saga for a windscreen judder.
AA: A set of three latest revision ( 2023-24 ) wiper blades arrived for the Plus Six. They are all slightly different lengths and are specific to position, details as follows. Note the part numbers and locators are for a right hand drive car.
Y361048 31077-SWA-SC Marked as no 1 on reverse of blade and goes on the offside spindle.
Y361049 30941-SWA-SC Marked as no 2 on reverse of blade and goes on the middle spindle.
Y361050 31044-SWA-SC Marked as no 3 on reverse of blade and goes on the nearside spindle.
The blade width of the arm is very very slightly reduced from the previous arm version where it enters the wiper blade, they fitted the present aftermarket wiper blades fine with a slight bit of crimp needed where the arm locates, using parallel pliers on the wiper blade, being stainless this can not be seen.
The new arms are slightly changed to the previous version or are from a different manufacturer. Please see following photo showing the underside..
![[Linked Image]](https://tm-img.com/images/2024/01/31/Wiper-arms.jpeg)
There is now a fixed guard over the spring. The clamping screw appears to be a larger diameter, also on the reverse the counter sunk head of the same screw is larger, I assume for better force ( tightness ) distribution across its securing cap.
Note: In the photo of the old arm ( left in picture ) you can plainly see the retaining cap that goes over the spindle has become oval!, the new ones are round. This has happened on all three of the old arms and partialy explains why it was a poor fit on the wiper spindle.
Once fitted the spring tension of the replacement wiper arms was exactly the same as the old arms being 1.5 lbs.
The new arms eliminated the play seen on the old wiper arms at the fulcrum pin. However, all three new arms needed a slight tweak of angle undertaken on the arms to make sure the wiper blade rubber sat at 90 deg to the screen.
They did not hugely improve the judder. I removed all the arms and refitted one at a time. Each arm would judder in any of the three positions and as each of the remaining arms were then connected the judder stayed fairly the same across all arms..
BB: Windscreen clean. Firstly with a clay bar ( very little dirt picked off the screen ) than with a proprietary screen cleaner, then with a windscreen polish, this was repeated 4 times. The result was a very very clean and smooth screen with no residule coating left on the screen. I chose both a cleaner and a polish that guaranteed to leave no residue or coating behind. ( choose carefully on this, as some do )
All the judder tests were undertaken by using the wipers with a water mist
All the wipers still judder slightly, but nowhere near as violently as previously, much smoother in operation...
Conclusion so far, by far the biggest difference was by both cleaning and then hand polishing the windscreen, making the surface as smooth as possible and removing the old coating ( The glass polish reduced the judder more than just cleaning ).. This makes some sense as a polished surface would help reduce friction between rubber and glass..
Next Step. I will see if the judder stays at the present level as I could just about live with it as is, alternatively, the wiper arm spring force might be able to be reduced by stretching the wiper arm springs, but this may need careful thought as the new arms have the protective guard over the spring.
Dave
