Start at the tyres and work your way in to the diff. If it was between the diff and the transmission it would be a faster noise. Also, check to make sure the diff cradle is solid and no loose/missing bolts.
with the wheel bolted on and the car jacked up solidly, give the wheel a good "wiggle" by hands. There should be no play. If there is movement in the wheel other than rotational than you a wheel bearing problem
I recently had a knocking as you described that was driving me mad, mainly on right hand turns but also going straight ahead after a turn. I thought it might have been the diff again (LSD) which made a similar knock a while back but disappeared after an oil change. It turned out to be one of the CV joints on the left hand drive shaft. I could see where the grease had oozed out over the years so I removed the rubber boot retaining clamp, pulled the boot back as far as I could and packed some grease in there and no more knocking. I used a cable tie to secure the boot temporarily, I need to get a proper clamp back on there.