Originally Posted by J Mac
My bike rack has a threaded pin instead of a J pin and when wrenched tight there is no wiggle room.
Same with my rack (which is used directly on the van or motorhome, not the trailer, but the logic is same). Instead of a pin going right through, a bolt is inserted in one hole of the receiver box and threads into the square shaft of the rack, pulling it tight against one side of the opening. This would not be suitable for the load of towing, but works well for the rack.