Hey guys, I'm asking on behalf of my buddy. He has a 96 escort wagon, 1.9 auto. When driving the car at any speed the speedometer bounces back and forth.

For instance when driving about 70 mph down the interstate the gauge swings back and forth between 60 and 80mph, it never stays in the place.

I was wondering if anyone had any ideas of what to check for. I was thinking of checking out the speedometer cable but I figured I'd ask what you guys thought first.

 

You probably have a kink or some other defect in your speedometer cable.

 

Sometimes you can lube the cable to make it work right, I'm not sure if that'll work with that car though. I'd probably just replace the cable.

 

My '95 Tracer has the same problem and my dad's '94 Taurus did too. It's not the cable, it's some defect in the speedometer itself. Dad had the speed-o replaced in his Taurus, but my Tracer's a five-speed and has a tach, the speed-o's $300+ so I said the heck with it. The odometer still works fine, it's something in the speed-o needle's drive.

 

Just general ideas since I do NOT know about this model.

Most speedos work either thru an electronic speed sensor which is usually tied into the tail shaft of the tranny or the differential. I assume the Escort doesn't have either so the sensor must be just plugged into the tranny casing. Electronic speed sensing works thru the computer and gives a signal to the speedo to display the correct speed.

Or, older speedos have a mechanical cable that is usually tied into the tranny and is routed thru the engine bay thru the fire wall and to the back of the speedo itself.


The electronic sensors can go out and cause all sorts of symptoms such as bouncing speedo, and no speedo, cruise control working intermittantly or not at all and harsh or strange shifting. Usually replacing the sensor fixes the problem.

Mechanical speedos usually show a bouncing needle because of lack of lubrication or damaged cable. If you drip a little oil down the back side of the cable from the speedo, that usually helps. Also check for frayed steel cable and cuts in the plastic tubing. I like the cable lubricators you can buy at Motorcycle shops. They plug into the end of cables and allow you to use spray can lubricants to force lube all the way down the cable.

Another possible cause of bouncing speedo is that the speedo may need lubrication itself. Don't know on a Ford, but some speedos can easily be taken apart and you can LIGHTLY lubricate the needle bearings with a LIGHT oil. Once in my life(and no I don't play with speedos much) I have seen where the magnetic coupling will be bent and touch(sometimes it is just dirt) the other half of the coupling which will cause bouncing. Easy to bend the "wings" back out of the way, but it WILL affect the speed reading you get. Also this is how you can adjust your speedo for correct speed, at least on the old fashioned type speedos. A tiny change in the bend will make a noticable change on the indicated speed.

Good Luck,

Jim Henderson