Dear Neil,

Good p.m. and may this find you well. On 940 series cars, the splined shaft - onto which the wiper arm is secured with a hex nut - is part of the mechanism, that connects the motor to the wiper arms.

The metal at the lower shaft end (that opposite the splined, threaded end) is pressed down, so that it resembles a round-head screw, but without any slot. This cannot easily be removed: the head would have to be ground away. It could not then easily be re-used. The mounting for the shaft housing slides into a square metal "beam", and is secured to the beam by indentations into the metal. This, too, would be hard to remove.

In short, if your wiper transmission mechanism has worn out, you can:
(a) get a replacement from a dealer (see www.borton.com)
(b) go to a salvage yard, and remove one from a 960 series car.

I do not know if the wiper mechanism for a 940 series car will fit on a 960 series car, or vice-versa.

To access the mechanism, on 940 series cars, one must remove the "cowl", the section of body work just in front of the windshield. The cowl has the grille, through which air passes on its way into the ventilation system.

On 940 series cars, the cowl is secured by three fasteners. One is in the center of the firewall, behind wiring harnesses. There is a fastener at the point where the cowl meets the edge of the fender. This point is just in front of the hood hinge.

Hope this helps.

Yours faithfully,

spook