Speedometer issues

[justinlogue5_0]

Ok, When I bought this truck the speedometer would read 5mph faster once you hit 50 mph(meaning at 50 you were really running 55) This drives me crazy! So I bought the Hyperteck programmer because it was supposed to fix this plus the extra power wouldn't hurt either I guessed. I had to play with it for ever to finally get it with a mile of being correct. But I have now noticed that the miles aren't correct. What do I need to do to get it all fixed where I can get rid of the programmer and get a TW 6 pos chip with out the speed ometer being way off? Oh and my tires are 285/75-16. Thanks!

PS-Ford said that the sensor in the rear end either works or it don't. So I pulled it out and cleaned it at least anyways.

[justinlogue5_0]

Anyone?

[justinlogue5_0]

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Have ford recalibrate your speedometer? I'm guessing its because your running 285s. When I was running 265s (stock size) my speedometer was running 2.5ish mph fast. So at 50 i was going 52 or so. I just learned how much faster I am actually going when I got 35s.

[justinlogue5_0]

Can they actualy test it after the flash,or are they just going by the tire size? I think what I am trying to ask is what if they flash it and there is actually some thing else wrong and its still off and I don't know untill I see blue lights in the rear mirror?

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They could test it with a gps if someone there has it. Not exactly sure how they recalibrate it, I just know that they can. Is it off 2.5 mph at 25?

[justinlogue5_0]

I am really not sure. I never tested it that slow. I started around 40mph and it seemed ok till you hit 50 then it would just seem to jump ahead 5 mph. I guess it doesn't hurt to give it a try at Ford. Only charge me a half hour I guess.

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I wish someone who knew a little more than me would chime in. I would just call them and ask how much it would cost to get it calibrated so you dont pay an arm and a leg for it.

[justinlogue5_0]

Thanks for the reply BTW I love your truck

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Thanks. The way I deal with the speedometer being off, since im gonna drive 5-7 over anyways, that means a 50 speed limit im gonna go 55, well I just set my cruise on 50 and im going 55, 70 speedlimit i set cruise at 70.