Wiper Mechanism Link Arm - Help Needed

[kingzetts]

Can anyone help with any pictures of the component parts of the main link shaft which joins the short crank arm on the wiper motor to the ball joint on the crank arm on the central wiper spindle. This link shaft is a strange beast, and is well described with pictures in this link;

http://www.xkedata.com/resources/read/?id=9 (see the "why" bit in the second part of the article before the comments section).

It contains a cam which when the motor rotates on one direction changes the length of the link compared to when it rotates in the other direction. This is how the parking position of the wipers is made to lie outside the blade sweep - when the motor reverses to park, the arm length changes and moves the wipers below the bottom of the arc they reach when in service.

The cam is tensioned by a conical spring acting on a special washer locked to the motor crank pin which presses on the face of the cam. This provides sufficient drag on the cam so it is forced to rotate with the wiper crank arm shaft, turning within the link arm and changing its effective length, until it reaches one or other of its stops within the link, but then to be able to overcome the drag so the cam and link shaft can rotate relative to the crank arm shaft.

On mine the spring and associated special washers are missing leaving the cam untensioned, and the cam assembly itself is badly worn, with the result that my wiper sweep varies randomly according to where the cam has decided to sit - most annoying in the rain.

I can buy a replacement link with cam from RM Smith, but he can't supply the spring or special washer. I can have a go at making these but I am in need of some pictures of the missing parts to get a better idea of how the whole thing works.

Any help gratefully received!!