Early or Slipping 2-3 Upshift

1. Improper fluid level.
2. Improperly tuned engine.
3. Damaged or improperly adjusted linkage.
4. Cut or worn 2-3 accumulator piston seals.
5. Plugged 2-3 accumulator piston drain hole.
6. Damaged accumulator.
7. Dirty or sticking valve body.
8. Leaking vacuum diaphragm.
9. Worn governor seal ring or counterbore in case.