This is a common problem caused by lack of lubrication wearing out a plastic bush, it can be fixed easily if you are up to a bit of simple DIY. You will need a vice, centre punch + hammer, small drill bit + drill, washers and a split pin.
Use a centre punch to mark the spindle in the flat area just beyond the ball joint (you will understand when you have the wiper assembly off the car). You must punch the spindle to start the drill off, otherwise the bit will skip about as the spindle is hardened steel.
Using a sharp drill bit, drill a small hole just larger than the split pin right across the spindle (I used a 2mm diameter drill). Allow enough space for fitting a washer behind the split pin.
Clean off swarf, re-fit the wiper mechanism arm back onto the ball joint, fit a washer and split pin and gease the joint well. Job done!
The job takes no longer than 20 minutes per joint.
Trev, May 2007