Excessive Shift Shock When Upshifting or Downshifting

1. Defective vacuum diaphragm or rod.
2. Malfunctioning Control valve(s).
3. Defective accumulator(s).
4. Defective overdrive brake band.
5. Defective 2nd band brake.
6. Defective overdrive band servo.
7. Defective 2nd band servo.