I’ve got an 81Series III Santana and having issues or can’t get it into 3rd or 4th gear. I’ve been noticing a strange sound almost like a high pitched grinding and scratching sound when I accelerate through 2nd and sometimes 3rd ( when I could get into 3rd). I realize I still need to give the type of transmission but wanted to get this question out there first. No issues with reverse, 1st or 2nd. Would appreciate any advice and guidance.