Lincoln/Mercury Repair: Speedodmeter / Trans, torque converters, gas milage

Question
Today my speedodmeter quit working on my 97 (150k miles)Sable and it feels like I have no power steering. I checked the fluid level is fine, the belt is good (just 1 belt on the car). Ok not so bad, but then all of a sudden it wouldn't shift out of 1st gear. I checked the trans fluid is fine. I turned the car off and back on and pulled away and the speedodmeter was working and the car ran fine, shifted normaly, sterring was ok again, however when I stoped at a light and started to go again the speedodmeter stopped and the steering went and it shifts VERY HARD, but did shift. This repeted several times till I got home. When the speedodmeter stops working the car has no pick up and seems like trans probs, however when it starts (speedodmeter) working again the car is fine. Do (God I hope not) I have a trans problem? I would think if I did it wouldn't work fine when the speedodmeter works? (Least I hope n pray)  I thank you for your help.
TJ ozman0666@aol.com

Answer
Hey TJ,

You will owe me a good rating on this one... LOL Ok, your car is fully computer controlled. So... you have a bad speed sensor! Your onboard computer needs to know how fast your car is going to turn on and off the power steering and when to shift. I am 110% sure this is the problem. First, in the olden days, gas prices went crazy, from $.50 a gallon to a buck and America went nuts. Auto manufacture engineers rushed to figure out a way for vehicles to get better MPGs. Some of these where electric fans, lock-up style torque converters, ELECTRONIC CONTROLLED TRANSMISSIONS, power assisted power brakes, light body material, overdrive transmissions and SPEED SENSITIVE POWER STEERING. If the car has a bad speed sensor, then the onboard computer does not know how fast the car is traveling. New technology power steering relies on this to make the steering easy(parking lot) or to turn it off for gas milage on the highway. Well, I hope this gives you a little bit of an idea what is going on. Have a super weekend and this repair should make your check engine light go off...

Follow up: Oh, the repair should be around $150 tops...