This problem only started this morning!

When driving i can hear a knocking noise from the gearbox/drive shaft area! it happens when in gear, and even when coasting with clutch up and down in and out of gear

I have had the car up on jacks and rotated the wheels and i can hear the knocking and it seems to be coming from where the drive shaft enters the gearbox!

I have only had the car for 11 months and it was serviced before i bought it! could it be a gearbox oil problem i.e lack of?