try adjusting the linkage or you may need to pull the trans and open her up

Is the sound coming from under the hood or through your shifter cables?

usually this kind of sound is generated by the mains bearings in the tranny ( tapered bearings at the ends of each shafts ) This appear when the bearings got lots of mileage, so cage and roller a worn a bit and get noisy.

The noise seems to be coming from the front right of the car, but like I said leaves immediately when I pull the shifter a little left.
I may try adjusting the cables that is a good Idea.

If it was the main bearings would it stop if I pulled the shifter slightly left??

Yes, that could be a possibility.

Or it could be something in your shift cables raddling!