So i noticed that on my 240 the rear end makes this cluncking sound, so i jacked the car up and when i spin the rear wheels it makes this weird sound at the same pace as the driveshaft, if anyone knows what this is it would help becouse i dont know if its a wheel bearing or the rear end itself

 

There is no knowing about it, get to work! Jack it up, move the wheels by hand, run it in the air, check the diff fluid, check the U joints, check the brakes, etc.