Loud clunk on takeoff/brake

[ShugDug]

Hi,
This might be 101 to some of you more experienced vanners but I can’t figure out what the issue is.
Whenever I take off from rest or brake sharply, I’m getting a loud clunk (it’s actually more like a bang) from my caravan’s Drawbar. I initially thought there must be movement in the towbar but it’s new and definitely not that.
I’m aware there’s a damper inside the rubber boot at the front of the van. This is a 20 year old Swift Conqueror and I don’t know it’s service history. It feels like there’s no damping effect and the arm just extends and retracts relatively freely, thus the clunk.
Has anyone else encountered this or know what the fix is? I’d be really grateful for some advice.
Cheers
Ken

 

[camel]

I think you have identified the problem yourself it appears your damper is kaput,

 

[Jaydug]

I think you have identified the problem yourself it appears your damper is kaput,

Yes! The above reason gets my vote too. When your van is parked, try pushing the coupling head back towards the caravan. It should be difficult to push back - and also difficult to pull back out again. The easier it is, the more useless your damper is. If your DIY skills are up to it, it's not too difficult to replace - once you've found the correct one.

 

[Damian]

The issues you provide do in fact point to the hitch damper being non operational.

The drawbar should not move in and out freely, it should take quite considerable force to move it and it should return to its resting position slowly after being compressed or extended.

If you take the A frame cover off, on the A frame you should find a series of numbers, something like 811/011, this is the identification number for the hitch damper.
At the age of the van it may take some finding and cleaning but it will be stamped on the top part of the frame, usually on the right hand side as you look at the van.

Replacing is relatively easy but again at the age of the van could be more problematic, I think there are videos on UTube that may help, or get a caravan engineer who knows how to do it to replace it.

 

[ShugDug]

Thanks @Camel though at this stage I’m using more colourful language!

 

[ShugDug]

@JayDug, from one Dug to another, tx for your suggestion - confirmed it’s the damper. Wasn’t sure exactly how this worked as you can’t readily find an exploded diagram.

 

[ShugDug]

The issues you provide do in fact point to the hitch damper being non operational.

The drawbar should not move in and out freely, it should take quite considerable force to move it and it should return to its resting position slowly after being compressed or extended.

If you take the A frame cover off, on the A frame you should find a series of numbers, something like 811/011, this is the identification number for the hitch damper.
At the age of the van it may take some finding and cleaning but it will be stamped on the top part of the frame, usually on the right hand side as you look at the van.

Replacing is relatively easy but again at the age of the van could be more problematic, I think there are videos on UTube that may help, or get a caravan engineer who knows how to do it to replace it.

Thanks Damian, I followed your instructions, located the ID number, phoned ALKO Australia and should get the part in a few days. The chap on the phone literally said “strewth Mate, we don’t stock many of those...is it a pommy van?”
I’ll give installing a go - replaced shocks and springs on cars before so should be OK.
Appreciate your detailed response, tx again.
Ken

 

[JTQ]

Did the person installing the new hitch simply overlook getting the rearmost fixing bolt that goes through, to also do its other task and pick up the dampers's end fixing eye?

 

[DaveA1]

Thanks Damian, I followed your instructions, located the ID number, phoned ALKO Australia and should get the part in a few days. The chap on the phone literally said “strewth Mate, we don’t stock many of those...is it a pommy van?”
I’ll give installing a go - replaced shocks and springs on cars before so should be OK.
Appreciate your detailed response, tx again.
Ken[/quote]

Like the feedback, be careful of the PC brigade. :lol: :lol:

 

[Damian]

Did the person installing the new hitch simply overlook getting the rearmost fixing bolt that goes through, to also do its other task and pick up the dampers's end fixing eye?

I do not understand this posting...……..what new hitch? nothing has been done yet, apart from the OP ordering a new damper.

 

[JTQ]

Did the person installing the new hitch simply overlook getting the rearmost fixing bolt that goes through, to also do its other task and pick up the dampers's end fixing eye?

I do not understand this posting...……..what new hitch? nothing has been done yet, apart from the OP ordering a new damper.

Okay you are correct, I had miss read it, just the "towbar" was stated as new..

 

[Thingy]

Some of you may remember my issue a few years back with a very similar sound, and I immediately thought the damper. However, on examination we found excessive vertical play on the whole front assembly. The dealer was next to useless and in the end we had Al-Ko come and inspect it, and they immediately failed it. This was a brand new caravan. The inspection cost me around £100 ish which I eventually got back from the delaer.

To check, we could simply get hold of the hitch head and waggle it up and down. Not to be confused with rotational movement which is normal.