i have a 2000 f150 4x4 7700 and when im driving sometimes the speedometer will bounce and jitter around. its also not smooth when accelerating. when i put on the cruise control the speed stays the same but the speedometer still dances around. how can i fix this and make it smooth and accurate again?

thanks

 

no one??? come on now

 

I'll tell you what I know, which is not much. I'm pretty sure on a 2000 truck the speedometer is electrically driven by a "geared" sensor (possibly a generator of some kind) on or near the rear axle. The speedometer does not get its reading through the PCM, but, the PCM has to get the vehicle's speed from this same source so it will know when to command shifts. It sounds like a poor connection somewhere between that sensor and your speedometer.

And, that's about all I can come up with. Sorry!

- Jack

 

thanks atleast you gave me some input

 

anyone else???

 

I was told different tire sizes may do this?? Correct me if I'm wrong.. mine does this too, but I was just thinking it's because my tires aren't the sizes on labeled on the door.