Like it says, got a 1990 DX with the 1.5 and when I decel in 1st and 2nd without the clutch engaged, there is a grinding gear sound. When the load is off with the clutch in it's fine of course but does anyone have an idea what is causing this noise?

Accel in 1st and 2nd are quiet but 3rd, 4th, and 5th have some noise during accel but not decel

 

My buddy had this same situation in his car. It did it for the longest time until one day it took a sh*t at a light on a hill. When we got it out and tore it apart the input shaft was shredded. A couple of gears had some damage too but not near as bad.