What sort of hitch?

HI Tim
I dont think they are talking about the tow ball they may be talking about the tow bar as it my not be correct size for the weight you are towing

Look up the vehicle manual and look at the towing and see what the size of towbar you have and then look at the weight of the caravan .

Go back to the people who sold you the towbar and tell them you must have a heaver towbar
Terry

Did he give any reason? The only thing I can think of is that a van of that age may have an imperial sized coupling (1?") and the ball on your tow bar is metric (50 mm.) This does not make for a good fit.

Types of Caravan Couplings/Hitches

Here you go Tim, a link to the various types of couplings available.
Hope this helps.

Cheers
Glen

Have a look at the OzHitch