extravagant screen wipers

[silverdorking]

Advice please
How do I stop my 'clap hands' wipers shooting off the outside of the screen - Is it to do with the limit switch?
Thanks Andrew

[8009STEVE]

On the bottom of the stroke, how far away from the screen rubber does the blade stop?

[silverdorking]

It swings out about 10degrees beyond the screen external vertical edge- thanks for your interest
Andrew

[silverdorking]

In response to rereading your posting- on bottom of stroke, blades park on the lower screen horizontal rubber- is that more helpful?
Andrew

[rayofleamington]

have you always had this problem?
Limit switches are not a part of the Minor wiper system - the swept angle is given by the mechanical geometry in the wheel boxes.
Later cars have a self parking function, but this merely allows the motor to switch off in the right place, and can not not affect where the wipres go to at the ends of the swept travel.

There are 2 causes I can think of:
1) you've got the wrong wheel boxes (the little gearboxes that the wiper spindles come out of). The swept angle is different on later cars and therefore not compatible.
2) Most common cause - the wheel box has loads of slack in it (backlash). This allows the wipers to travel a bit further when they should stop at the end.

to check for backlash - pull the wipers off the screen a bit and try to rotate them. I don't know what is 'good vs bad' in terms of how much backlash is present but if the amount you get is similar or bigger than the overshoot then it's really not helping.

To fix the backlash, you can replace or fiddle with the wheel boxes. To renovater, you need to strip them down and move the gearing onto unworn teeth, re-grease and use a new cable.

To fiddle them, remove the wiper arms and mark the position of the spindles. Remove the cable from the motor gearbox and rotate the cable - this will gradually rotate the wiper spindles. Continue until the mark on the spindles is 180° from where it started, and reassemble everything.

on final assembly, make sure you fit the wiper arms in the correct location on the spindles, otherwise they can sweep down on to the bonnet! (by parking the spindles at the botton of the sweep and fitting the arms at the bottom of the sweep)

[silverdorking]

Thanks very much for this comprehensive reply, which I will now digest and report back on success, thanks again
Andrew

[bmcecosse]

Ray's 'fiddle' method ^^^^ works - and gives you brand new unworn sections in play - should be good for another 20/30 years !