Contamination may have built up on the pads which could be due to grease on the towball, spray from the road, diesel fumes or failure to remove all of the coating on the towball.
To remedy the creaking you need to rub the towball with fine emery along with the internal friction pads inside the hitch and because the pads are manufactured from the same material as brake and clutch linings you need to clean with Brake & Clutch Cleaner. I suggest using 'Holts' brand as it's not only quick drying but you can also turn the can upside down which is ideal for spraying up into the hitch. You can read more about the product in the link provided.
We've also got a Winterhoff doo dah. When we first got it, I was like a woman possessed cleaning, (and I am NOT know for any cleaning malarkey unless it is for my beloved tin tent), the tow ball with meths and kitchen roll having been advised this was the best way to keep it dirt free. Then I'd put a plastic bag held in place with an elastic band over it after use before replacing the tow bar cover BUT........ time has passed and so have my enthusiasm levels for cleaning anything so I only hope that our connection remains noise free from here on in.
But we used to have a helluva creaking on our much last tin tent which was 16 years old when we traded her in for Ellie. Caused for some very funny looks as we'd pass folk going around bends
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets