A grinding noise suggests a bearing at fault or perhaps worn pads on the brake rotor.
However, the clunking noise you mention could also point to a problem with the drive shaft or differential.
The first thing you should do is to get under the vehicle and try twisting the propshaft back and forth. If there's any movement this points towards a worn universal joint on the propshaft. A worn universal joint can cause a clunking noise - particularly when pulling away. The vibration caused by a worn universal joint can also damage bearings in the differential and also to the splined ends of the axle shaft.
You're also going to have to remove the wheel from where the noise comes from and examine the end of the axle shaft/bearing.
Answers & Comments
A grinding noise suggests a bearing at fault or perhaps worn pads on the brake rotor.
However, the clunking noise you mention could also point to a problem with the drive shaft or differential.
The first thing you should do is to get under the vehicle and try twisting the propshaft back and forth. If there's any movement this points towards a worn universal joint on the propshaft. A worn universal joint can cause a clunking noise - particularly when pulling away. The vibration caused by a worn universal joint can also damage bearings in the differential and also to the splined ends of the axle shaft.
You're also going to have to remove the wheel from where the noise comes from and examine the end of the axle shaft/bearing.
The link below is of images of the rear axle:
land rover discovery rear axle Google Search