Our last linkage was fitted about 2.5 yrs ago, my understanding is small changes were introduced after 2021 on the Plus Six, or the linkage assembly qc was improved, the linkage is very adjustable, certainly the 3rd wiper linkage set now fitted is better made than the originals. The wiper arm design was changed as well.
One thing to check is see if the wiper blades are hitting the screens lower metal edge when in operation, its better to squirt a hose on the screen while checking, as that helps in reproducing a constant wet screen.
Our 2nd set of linkages varied the park position of the blades and the blades would hit the lower screen edge, they would never keep the same park position, as the trunnions were semi siezing at times.
On the Plus Six the early wiper arms were updated, as the locking screw kept coming loose and then the wiper arm would come off, the early wiper arms would distort where they fitted over the trunnion splines thus allowing the locking screw to work loose. I ended up fitting the last variation of arm and blade and using a small amount of locktite blue on the retaining screw. I check them periodically but they have been ok for over 2 yrs now.
