Harsh N-D or D-N Shift

1. Improper vacuum signal to modulator or defective modulator.

2. Broken reverse servo cushion spring.

3. No. 5 check ball missing from control valve (harsh into reverse).

4. No. 6 check ball missing from control valve (harsh into drive).

5. Broken forward servo cushion spring.

6. Thermal element does not close when hot.