i got a d16y8 and i pulled it out of my dads car which it started making a grindign noise when clutch was out so we replaced the clutch surfaced flywheel etc. replaced the throwout bearing everything and then i put it in my hatch and about 40 miles of driving it started doing the same grinding as if throwout bearing is already bad. any ideas why it would go through a throwout so bad?

 

When does it grind? If the clutch pedal is depressed when it grinds its the throwout/release bearing. If its grinding when the clutch pedal is up (IE clutch engaged) then the transmission input shaft/mainshaft bearing is bad.

 

it grinds when it is depressed example idlinf and like i know its the throwout but i literall replaced it 100 miles ago y would it go bad so quickly?

 

Possibly contaminated with dirt/sand if the flywheel inspection plate was missing. It also possible the bearing was just bad out of the box.