Hi John,

The shaft bit has vertical ridges in it - take the arm off and clean
these ridges out with a pointy tool, then put the arm back on.

The arms seem to be a soft metal that gets cut into by these ridges, and
eventually it lets go, leaving the ridges full of the soft metal from
the arms.  Tightening it won't help much as there's nothing to bite into.

toodle pip,
--
       Dug Smith          | Terry Pratchett: It's almost
(mailto:dug@dugbert.com) |  impossible to ride a rock and roll
(http://www.dugbert.com) |  motorbike and stay on for three verses.

On 5/28/2026 18:12, John Lauterbach wrote:
> How do i keep the wiper arms from slipping around the drive shafts?  Even tightening the nut doesn’t help.  Yesterday wipers were running fine and suddenly driver’s wiper stops working but right side keeps going.
>
> thank you
>
> john