I am having lots of trouble shifting from 1st to 2nd or from neutral to 2nd. Almost feels like the shift lever is stuck when I try to shift. It is fine shifting throughout the rest of the gear range, and fine when shifting down into 2nd from 3rd. I am using rotella T4 15-40. Could it be a mechanical issue or maybe just oil related. Maybe I can add some ATF to see if it helps?