A slightly different take on repairing the wiper arm……..
The thing I like about fixing old machines is getting into the mind of the designer and production engineers to understand how the design came about. They were under different constraints, (time and money mostly), than a man in a shed but they can use some elaborate techniques hard to duplicate by a humble restorer. However, with only one car to fix then maybe the original design can be improved on, take the windscreen wiper for instance.
The design of the joints at the end of the wiper arms was never going to be the best, soft aluminium rivets, un-lubricated and out in all weathers were never going to last forever and next to impossible to service. Added to this the pressed shape of the L piece with the indented groove on top takes away underneath any flat thrust face for the two bearings. To work around this the bearing is a ‘top hat’ shape taking the face loading to the aluminium rivet. It works but is far from ideal.
This is what I did……….
I Pulled the wiper arms off, (with 2 leg puller), carefully drilled the heads off the rivets then as they still would not come apart sawed though the rivets and bearings to get the assembly apart. Each wiper arm was stripped of it’s original bearing and drilled through 10 mm. New bronze bushes were machined to be a press fit in each side of the arm and reamed through 8 mm. The L shaped bracket was also drilled 8 mm. The novel part of the exercise is the new shafts, they were made from bicycle brake caliper retaining nuts, basically an 8 mm tube tapped M6 with and allen key socket at one end. These were machined to length to suit the L bracket. I wanted slim pan head type screws but as these were not readily available I machined two from M6 countersunk screws. In my spares cupboard I found two plastic nut caps, cut down to suit the nut heads and also a couple of plastic caps which click into place into the screw heads, these will touch the windscreen first if the bearings wear out again and the joint becomes floppy.
Now the wiper arm works nicely again and in a couple of years or so can be easily dismantled and relubricated.
View attachment 72382
The picture shows the parts ready to be assembled
GrahamH
