I have a new 2007 Swift challenger. On all previous vans I have had no problems with the wheel but on this van when using it again this weekend the jockey wheel has come unsrewed in the middle and come totally apart, this has exposed a lot of grease and ment that I have had to get down and put the wheel part up through the hole and then rejoin it up with the top part.A really messy job. Should the wheel come apart? On this caravan the jockey wheel come up through the middle of the hitch, not clamped to the side. any help would be appreciated.