Passing gear on hydramatic

The downshift from 4th to 3rd in "Drive" should occur at 15 to 11 mph at closed throttle, 19 to 16 mph at full throttle and 60 to 15 at forced throttle. Your passing gear (kickdown) only should work if you are below 60 mph and goes back into 4th at 65 or when you let off of the gas pedal. Kickdown is easily adjusted with a 3/8 open wrench by adjusting the nuts on the rod. Don't get carried away with the adjustment. Do a 1/4 turn and then drive the car to see if it is any better and readjust as necessary. The kickdown winds my car up a bit too tight for my tastes, so I rarely use it.