grinding in second
That sounds like the 1st/2nd gear slider. If you have missed the 1-2 shift that will happen, the edges of the slider gets dammaged then cause the shifter handel to rattle when makeing the shift because the rough edges prevent the shift from being made smoothly. Thats how it was explained to me when I had to have the 1/2 and the 3/4 sliders replaced in my T-5Z. To many missed shifts.
This horse runs.