When the wheels are off the ground the axle turns okay and the wheels turn but when all wheels are on the ground they stop turning as does the axle and it makes quite a noise. My research would suggest this may be a clutch problem but both are less than 6 months old and have worked fine until now. Any suggestions would be gratefully received.
Normally the test you stated would say the wheel clutches are worn, but if the axle also stops turning when dropped onto the ground then this points to a different problem. I would check the axle to gearbox connection is not broken or depending on the connection your golf trolley is built with. I would try to check the outer metal sleeve coming from the trolley gearbox is turning, see photo. IF this part of the gearbox also stops turning then it points to a fault inside the gearbox. If this part is turning ok I would look at the connection (pin) or (ring grub screw ball-bearing) to make sure it is connecting the axle with the (sleeve) gearbox.