Harsh 1-2 Upshift In "D" Position
Pump assembly, valve body (TCC shift valve stuck or damaged), incorrectly tightened valve body bolts (cross-leaks), 1-2 accumulator or 2-4 band and servo.
Pump assembly, valve body (TCC shift valve stuck or damaged), incorrectly tightened valve body bolts (cross-leaks), 1-2 accumulator or 2-4 band and servo.