Welcome to the forum and to the 300,000 + miles on the ODO <img src="/forums/images/graemlins/kewl.gif" alt="" />
Now, that grinding noise that you are talking about is it when you depress the pedal?
When you say that when you drop the clutch in neutral it makes a whining/grinding noise I assume that the car is in motion, right?
It not necessary is your tranny, it could be your throw out bearing/Clutch/pressure plate or all of the above.

When was the last time you had a clutch job?

88 red Montero with the Dakar Special Edition decals, 438,000 miles (As of 7/23/2012) some occational blue puffing but still strong and counting!!! I am going ppsshhh (turbo), Stay tuned =) ...