No 3-4 Upshift In "D" Position
Low line pressure, valve body (3-4 or 1-2 shift valves stuck or damaged), incorrectly tightened valve body bolts (cross-leaks), coasting clutch assembly or 2-4 band or servo.
Low line pressure, valve body (3-4 or 1-2 shift valves stuck or damaged), incorrectly tightened valve body bolts (cross-leaks), coasting clutch assembly or 2-4 band or servo.