Abstract: A gear coupling adapted to be capable of absorbing torsional shock loads between a power driven shaft 1 and a power drive shaft 2 comprises a drive member 3 and driven member 4 which extend from two sides into, and engage with, hollow intermediate member 5 so that the three members rotate in unison. The driven member 3 and preferably also the drive member 4 engage the intermediate member 5 by helical gear teeth 3B, 5A, 4B, 5B and a resilient member 6 such as a bank of disc springs is present between the drive member and the intermediate member. The coupling is arranged do that under the influence of a torsional shock load, the resultant axial separating force urges the intermediate member against the bias of the springs, to thereby reduce any damaging effects of the shock load.