Suppose that all of a sudden your vehicle makes alot of grinding noise in 3rd and 4th gear and when you hold the shift lever over to the right, you can feel the interference with the gears (bad feeling).... then you take out the gear box, take off the inspection cover and discover that nothing 'looks' bad at all. No filings (brass or steel), all the gears 'look' clean and sharp, shifting through them is easy, ATF looks great. Could it be the overdrive gears? There is a slight rattle like the sound you get when you have a bad reverse gear in a VW bug (hollow knocking sound). I have a spare transmission, but I would still like to know what has gone wrong, who knows, maybe it will be an easy fix. Thanks for any ideas. Chad.