Two things that might help locate which side:
- One get on your back under the car and grab the drive shaft strongly in the middle (wear a rubber glove they will be filthy) then try and wiggle (hard) the drive shaft..left, right, up down all around, mainly back and forth from the back of the car to the front of the car.
It might give you and idea if its loose or moves around a bit. Mine did move a little the new ones dont at all.
- Test it under load.
I found an uphill road with a small roundarebout at the top in a small village in France.
There was no one about not even a dog. No cars nothing.
I stopped the car 10 yards below the rounderbout and from there I started the car and in 1st (it was a steep hill) then went around the rounderbout (all uphill) anti clockwise. full lock.
There was a clonk clonk clonk form the righ hand side.
I then returned to my starting position and went round the rounderbout Clockwise. full lock.
I was listening to the front left side of the car. There was no clonk clonk clonk. maybe a very slight noise but nothing like the right hand side.
It was so much under load and turning uphill (both ways) the clonk clonk clonk was very clear which side it came from. I mean very clear no doubt whatsoever.
If its still not clear Then maybe its both at the same time, and you will need to change both.
Just need to find an uphill left turn and an uphill right turn with no-one on them.
Good luck.