A connecting device is disclosed for joining a trailer to a towing vehicle for substantial horizontal and vertical pivotal movements, as well as longitudinal rotation, of the trailer relative to the towing vehicle. A shaft added to one yoke of a pair of yokes comprising a universal joint is journalled in a block for rotation through 360 degrees. A similar shaft having a stop at its outer end and secured to the other yoke of the universal joint is inserted into a split block which functions as a quick-release clamping device upon closing of the block to secure the shaft. The bearing block preferably is affixed to the tongue or tow bar of the trailer and the split block is secured to the towing vehicle, the connecting device may be reversed end-for-end.