Clunking from the rear
 

Hello everyone I have been lurking the forum for a few years but now Im in need of some help.

Recently the car has been making a single clunk when setting off, similar to a stuck brake pad but that is not the case. The last couple of days I am getting a loud clunk from the rear when I apply power. This mainly happens at low speed in second, as the car jerks under load there is a very defined clunking noise. It also happens when moving forward from a backward roll. (Feels almost like backlash on gears)
I have tightened the axle nut and checked under the car for anything loose. Car drives and sounds fine apart from this
If anyone has any idea what it could be that would be very helpful.

If you've done the approved wheel re-torquing method (have a search - involves high torque setting, and then 45° Turn more) then maybe check your drop links, if they are loose or excessively worn they can make a noise.