RayI thought the alko ball only came in contact with the friction pads?
my soon to be 6 year old alko hitch and ball, has never made a noise, i always keep the ball covered, and apart from rubbing my hand over the ball, never clean it, nor have i done anything to the original pads, still have the spare pads.
So i don't think the noise is normal?
It may be that your hitch doesn't groan BECAUSE you haven't cleaned it and there is insufficient friction to stabilise properly.
To anyone fitting new pads, do read the Alko instructions as the pads need shims adding/removing to ensure the correct pressure on the ball.
Mike