I've a little transmission leak, perhaps the axle seals.

I couldn't verify the exact location of the leak, I only know that the ATF level was down since last checked.

When I last did a ATF change (3k ago), the drain plug didn't have what I think to be an excessive amount of metal or sludge clinging to it.

I know that if it is indeed the axle seals, my differential carrier bearings may be of the bad sort.

Is there some type of check or test I can perform?

Keep in mind - NO whine, NO slipping, NO blinking D4, NO hard shifting, none of the 'bad tranny' symptoms I've read about.