I just thought I will throw this in the mix - on our a6 the linkages are not that bad but the shafts on which wiper arms attach are worn, water gets in the bushes causes corrosion buildup that slows and even locks up movement. I clean them and grease with ACF50 2 or 3 times a year to keep them going otherwise resistance is too great and just triggers over current protection

The Laird donated his 3 spare windscreen wiper mechanisms to me today rather than get the house removers to move them to his new house so I thought I would start looking at the issues. Investigation of the three mechanisms appears to show that shows that any play in the system seems to be in the connections either end of the 2nd, short, arm between the gold coloured arm on the motor drive shaft and the first (driver side) wiper actuator.
Looking at one of the joints shows (2nd picture) shows considerable wear wear whereas the second one (despite the torn seal) seems to have more unworn metal. So I have re-assembled the good mechanism (with a good motor) using lots of EP grease in the joint, and will look to put this in the car as soon as I get it off the jacks in The Lairds garage where it is awaiting re-furbished calipers!!

Wierd Behaviour
 

Having finally got around to fitting this mechanism last night (well i was out the country for two months) and this one shows some strange behaviour. The parking position of the wipers appears to be in the middle of the arc swept by the wipers and not where it should be. i.e. at the bottom of the sweep :Confused:. I had made sure that the motor drive arm was bolted up with the mechanism in the same (parked) configuration as the one I removed. I need to investigate further today but any ideas??

The relevant pages of this manual might help adjust David?

http://forum.a8parts.co.uk/attachmen...5&d=1420350463

Thanks - buts its not adjustment but where the system "thinks" the parked position is. At the moment it thinks its in the middle of the sweep!

Yes I get that but it must mean the mechanism has slipped around and needs adjusting surely?

I dont think it is the mechanism - but i might be wrong. Perhaps I wasnt clear but it sweeps either side of the parked position. If I were to adjust the mechanism so that the parked position is at the bottom of the screen it would try to clean the engine bay and half the screen :)

Neil is right - the motor spindle and arm are in the wrong place relative to each other.

Remove the wiper arms first. Then remove the arm from the motor spindle and run the motor through a complete cycle until it stops in its park position. Then, set the mechanism to 'parked' and put the arm back on the spindle and run it through a couple more cycles to make sure everything runs smoothly. Finally, put the arms back on in the park position.

:)

I did indeed try to do that but maybe I got it wrong. Its all off the car at the moment and I will do it again when the midges allow - its an overcast, damp day here and the midges are fierce :(.

I changed the motor to the one that just came off the car and, after mounting the spindle in exactly the same way, the wipers now function as they should+++ ...and it has got rid of the annoying, noisy over-run caused by slapping on the scuttle and the drivers side pillar. Result. (even had some rain in which to test it!)
So, just little wear on the various joints, when accumulated throughout the mechanism, causes significant oversweep which, in my case, amounted to some 30-50mm at either end of the sweep. I just hope that this refurbished -but still 2nd hand - mechanism lasts a few years.