Back Driver side wheel stutters when turning

So basically every time I make a left turn, my back driver side wheel stutters or almost struggles to turn. The Right side is completely fine. I had my father make a turn while I inspect from the outside and I can physically see the back wheel struggling and jerking to turn. It vibrates when turning unless I am going straight but only does this when turning left. I highly doubt its the Rear Diff as I drained and added additive twice after the problem not going away. It is an 07 2WD Tacoma Sport. Anything helps! thank you!!

 

If the diff is the problem, a fluid change isn't going to fix anything.

Is the end of the axle where the brake mounts dry, or might that be wet?

 

If the axle seals aren't leaking on the shoes like Bill mentioned ^^ it sounds like you have a limited slip differential problem. The earlier Sports had a mechanical LSD