This grinding has been going on off/on for a while now.
When it does happen I hear/feel it for a second when I shift into drive.
I notice it when I first start moving and even more as I'm slowing down to a stop.
I feel it in the floor closer to my left foot and it also sounds like it'* coming from the left.
I can feel it very faint when I'm stopped in D with my foot on the brake.
When I put it in P it goes away.
It'* not the brakes or wheel bearing.
And I'm in the process of getting a new front trans mount since the rubber on mine started to seperate.
I think it'* worse when it'* colder out too.
The closest thing I can say it sounds like is a crunching wheel bearing but it'* still different. the crunching sound lasts a little longer and I can feel it in the floor.
Some days I can't feel or hear it at all.
Any ideas?

Mike..I forget..did you get a new trans in or are you limping the old one along?

Any expected ETA on the trans mount? Probably shouldn't be the mount, however it'* one less thing to factor in once it'* changed out.

Any possibility that it'* a strut mount bushing?

Bill, I'm still limping on the old one. It drives and shifts fine ever since I changed the fluid/filter a few months ago. I'm still nice to it though.
I actually just picked up the mount today. Unless something freakishly wrong happens, I should be able to test out the new one tonight.
Lash, I'm pretty sure it'* not the strut mount bushing. It feels further south than that.
This morning, at around 50 something degrees, it was acting up, and after work, at around 70 degrees, it wasn't acting up nearly as much. By the ride home, it was barely noticible.
The grinding also happens sometimes over bumps too.

The TOGs made it a tiny bit harder since I had to remove the fan but all in all it wasn't a big deal. Support the trans, loosen & remove the mount nuts, drop the front of the sub frame, remove mount then reverse. I took it out for a spin and the grinding is still there just as faint as it was when I came home.. I did notice a smoother feel to the car in general though.
So, whats next?

Not to scare you Mike...but er uh. Morty'* first symptom of a failing trans was a grinding on fully pinned turns. Next thing he was able to notice was a free revving engine in gear.

You've addressed the brakes, checked wheel bearings, axles are good.. unless somehow a strut mount is causing it .....I'm out of ideas and hope it'* not the trans giving you a final warning.

I've got my fingers crossed pretty much every time I drive it.
I've probably put 3k on it since I first noticed it too.
I was thinking maybe a stretched chain. I know I'm not putting down that much power but theres no doubt 6400 shifts have taken it'* toll on that or other things.