Weird Speedo

Out of no where my speedo started acting weird. I was on the freeway going on the on ramp and then all of a sudden it starts oscillating with no obvious pattern. It bounces around anywhere from 75-10 mph and never stays put. I have no clue as to what's causing this. The car otherwise runs as good as it was running the last couple of weeks. I didnt hear a pop or any wierd noises. All I know is, it doesnt give me mph. I think the odometer is still working, or at least its still somewhat increasing the number of miles.

Need help please

Al

Sounds like...

maybe a broken speedo gear in the tranny, or the speedo assembly itself. Bad cables usually make noise.

Lee

My car did this exact same thing when I first bought it. I replaced the speed sensor on the transmission ($30; easy to do!). Then I realized it was the little gear that snaps onto the end of the speed sensor. A few of the teeth were worn down, creating a flat spot. So every time the gear went around, it didn't know how fast I was going. The gear was like $7 from the ford dealer; they had to order it. You'll need to know the number of teeth on the gear when you go to order it, and what color it is (white I think, and had around 17 teeth). If you try to use your cruise control and it comes on, but shuts off after a few seconds, this is almost certainly your problem. Since the cruise doesn't know how fast you're going, it just shuts itself off. Make sure you put some transmission fluid on the new gear when you go to put it into the transmission.

Matt

Some more weirdness:

Speedo bounces around up to any mph in park/neutral if I revv the engine Also, all of a sudden, my steering got really sensitive in high speeds Before it was a little hard to go in from one lane to another, now I just jab the steering wheel a little and away I go

Al

It's probably the gear.

It's speed sensitive steering dum-dum! j/k If the sensor is seeing "low" speed, you're getting max steering boost. Must be pretty twitchy.

Lee

It's the speed sensor gear. Pull your speed sensor out and look at it. I'll bet you five dollars that it has some worn down teeth. If not, send me a pic and I'll send you the five dollars.

Matt