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Speedometer recal. 2001 f250 superduty

Posted: Wed Nov 02, 2016 11:21 pm
by j.osbourn80
So I have 35x12.50r17 (318/72r17)-metric conversion.. Bf Goodrich Ko2 tires on my truck. I have worked out that at 70 mph on speedo I am doing 77 via gps and my edge insight cts. I am 10% off on my speedometer I have also done the math and figured out that there are 601 revolutions per minute at this size. Tire size information is contained within the ABS module for this year model truck and there are several sizes listed within that it can be changed to. However my size is not one of them..... does anyone know how to manually enter this in or even if it can be done?

Re: Speedometer recal. 2001 f250 superduty

Posted: Mon May 22, 2017 8:59 pm
by akcooper9
j.osbourn80 wrote:So I have 35x12.50r17 (318/72r17)-metric conversion.. Bf Goodrich Ko2 tires on my truck. I have worked out that at 70 mph on speedo I am doing 77 via gps and my edge insight cts. I am 10% off on my speedometer I have also done the math and figured out that there are 601 revolutions per minute at this size. Tire size information is contained within the ABS module for this year model truck and there are several sizes listed within that it can be changed to. However my size is not one of them..... does anyone know how to manually enter this in or even if it can be done?
Any one have any luck on this?

Re: Speedometer recal. 2001 f250 superduty

Posted: Mon Sep 11, 2017 8:46 pm
by akcooper9
akcooper9 wrote:
j.osbourn80 wrote:So I have 35x12.50r17 (318/72r17)-metric conversion.. Bf Goodrich Ko2 tires on my truck. I have worked out that at 70 mph on speedo I am doing 77 via gps and my edge insight cts. I am 10% off on my speedometer I have also done the math and figured out that there are 601 revolutions per minute at this size. Tire size information is contained within the ABS module for this year model truck and there are several sizes listed within that it can be changed to. However my size is not one of them..... does anyone know how to manually enter this in or even if it can be done?
Any one have any luck on this?
BUMP

Re: Speedometer recal. 2001 f250 superduty

Posted: Tue Sep 12, 2017 1:14 am
by ThatOneDude
You may be able to change to one of the listed sizes and compare your as built data to see what changes, then apply your worked out tire rotations into that section of the as built data. I've never done this myself, so I can't be much help with anything more specific.

Re: Speedometer recal. 2001 f250 superduty

Posted: Sat Nov 11, 2017 4:03 pm
by akcooper9
ThatOneDude wrote:You may be able to change to one of the listed sizes and compare your as built data to see what changes, then apply your worked out tire rotations into that section of the as built data. I've never done this myself, so I can't be much help with anything more specific.
I downloaded the AS BUILT from the truck and online. Here is a screen shot of the current state of the ABS module in my 03 7.3 PSD. Note, the tires have been adjust by the FORD tool a few years back so I wonder if that is what is causing the 'error' in the two lines that say Tire Size. Any thoughts or suggestions on what to do next? I would really like to figure this out but need some help if possible. Thanks!

Image

Re: Speedometer recal. 2001 f250 superduty

Posted: Mon Jan 08, 2018 2:44 am
by fabrijack
when you adjust the 2001's with ford software you change the revs/mile in the antilock brake module. 600 rev/mile was minimum the system would take. I don't know if you can access this with forscan as I don't have my older superduty to test it on.
Hope this helps,
Jack

Re: Speedometer recal. 2001 f250 superduty

Posted: Thu Mar 15, 2018 5:28 pm
by delirious
join this facebook group. https://www.facebook.com/groups/2775094 ... oup_header

once added, do a search within the group under speedomter or tires. once found, it will tell you what to change and there's an excel calculator in there to either change the percentage off from your baseline code or you can enter your tire data. I haven't tried it but will soon.

https://docs.google.com/spreadsheets/d/ ... edit#gid=0