Adjusting speedometer
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From: Hawaii
Adjusting speedometer
After installing 265/75 16 tires on my 99 F150 4x4 4.6l, my speedometer is about 8% off. Can you adjust for this by installing a different size speedometer gear at the tranny?
Logistics Pro
Joined: Mar 2002
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From: Wake Forest, NC
Adjusting speedometer
No, you have to take it to FORD and they can use their WDM to reprogram the tire size. I went up to the 265's, but oddly my speedo isn't off. Maybe it was fast before :?
Chris
Chris
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Joined: Jun 2003
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Adjusting speedometer
Hey there I have an 03' 150 supercrew w/16" wheels,installed 285/75/16 tires and my speedo is right on. I was told by a ford tech that the trannies are all computerized and that the computer will adjust to the new tire over a period of time until it learns the new tire, or you can take the neg. batt. cable off for aprox. -10 min. re- install and drive your truck for at least 10 miles the way you allways drive it and the computer will re- learn it faster. Hope this helps you.
Logistics Pro
Joined: Mar 2002
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From: Wake Forest, NC
Adjusting speedometer
The tranny can adjust for driving and shifting styles and differences that new tires might make, but I don't see how its possible for it to adjust to the tire size! There is no way for it to know how fast its going outiside of the tire speed. The only thinkg I can think of is if it can compare tire speed to RPM but it seems like a long shot.
IF what you are saying is the case, it wouldn't apply to me because I checked the speedo right after I got new tires and it hadn't had any time to "adjust"
chris
IF what you are saying is the case, it wouldn't apply to me because I checked the speedo right after I got new tires and it hadn't had any time to "adjust"
chris
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Joined: Jun 2003
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From: Hawaii
Adjusting speedometer
I called all 3 Ford dealerships on the island and all said they cannot adjust the speedometer. 2 said it is against the law to do so and one said it will cause a code error. I would think that misrepresenting mileage would be against the law and I told the dealership that having my speedo off by 8% is only going to extend my warranty last that much longer. Any other ideas on how to adjust it? Maybe if I put 3.73 gears, it will compensate for the difference?
Hotshot
Joined: Aug 2002
Posts: 12,679
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From: BC, Canada
Adjusting speedometer
The speedo isnt reprogrammable as far as I know. You should be able to change the gear for the VSS in the back of the transfer case. If you pull the VSS out you can count how many teeth are on it and maybe try a gear with 1 tooth less to start. Our dealership stocks a few different gears, hopefully yours does too.
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Logistics Pro
Joined: Mar 2002
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From: Wake Forest, NC
Adjusting speedometer
Originally posted by CPerry
I called all 3 Ford dealerships on the island and all said they cannot adjust the speedometer. 2 said it is against the law to do so and one said it will cause a code error. I would think that misrepresenting mileage would be against the law and I told the dealership that having my speedo off by 8% is only going to extend my warranty last that much longer. Any other ideas on how to adjust it? Maybe if I put 3.73 gears, it will compensate for the difference?
I called all 3 Ford dealerships on the island and all said they cannot adjust the speedometer. 2 said it is against the law to do so and one said it will cause a code error. I would think that misrepresenting mileage would be against the law and I told the dealership that having my speedo off by 8% is only going to extend my warranty last that much longer. Any other ideas on how to adjust it? Maybe if I put 3.73 gears, it will compensate for the difference?
Illegal to adjust the speedometer calibration?? They must have thought you meant the odometer. What a laugh!
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Joined: Jul 2001
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Adjusting speedometer
Get the hypertech power programmer. It has the ability to adjust tire size and many other things like trans shifting and gear ratio's along with cooling temps and speed governors.
http://www.hypertech-inc.com/programmer.html
http://www.hypertech-inc.com/programmer.html
Logistics Pro
Joined: Mar 2002
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From: Wake Forest, NC
Adjusting speedometer
Originally posted by Racerguy
The speedo isnt reprogrammable as far as I know. You should be able to change the gear for the VSS in the back of the transfer case. If you pull the VSS out you can count how many teeth are on it and maybe try a gear with 1 tooth less to start. Our dealership stocks a few different gears, hopefully yours does too.
The speedo isnt reprogrammable as far as I know. You should be able to change the gear for the VSS in the back of the transfer case. If you pull the VSS out you can count how many teeth are on it and maybe try a gear with 1 tooth less to start. Our dealership stocks a few different gears, hopefully yours does too.
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