Could anyone advise me on a problem i may or may not have with my Knott coupling fitted to a 2023 Eriba Touring 540. After pulling up at a junction and then moving off, there is a clunk coming from the coupling as the free play is taken up, i assumed rightly or wrongly that this action should be dampened in some way for a much smoother take up in the coupling. Having owned 3 vans prior to this iv never had this problem before although they were Alco couplings. The van is stil under warranty and i intend to contact the dealer but would appreciate your thoughts as to be for-warned . Thankyou.

sounds like the overrun damper has failed

It does sound like damper failure but that usually occurs on much older vans. The test is to see if you can push the hitch in easily by hand. If there's significant resistance the damper is ok. A poorly damper usually causes a clonk as you brake as well.

Some other random thoughts:

Loose towbar securing bolts
Hitch grease needs replenishing (does hitch head wobble when 'shaken')
Hitch head securing bolts, if any, have loosened.

Usually when the damper has failed the Eriba brakes will start to dramatically snatch when you brake in the car, as I found out with my old Puck

I realise this is an older post, but I've had the same with our new-ish 2023 530. It also had a weird trick whereby it would turn to the right a bit when setting the handbrake. It seems like this has gotten better with age, so I guess it's possible this is something that just needs breaking in?

Hi Edwin,
I’ve got the same ‘banging’ issue on our new 550, collected just last week. We had it on site this week so didn’t find the issue until we were driving home yesterday.
Has yours settled in now?
I’ll be talking to ALV in the morning to see what they have to say.

Steve.