2nd Gen Non-Engine/Transmission Speedo calibrate

[stownsend]

Does anybody know what is required and how much does it cost to do the speedo calibrate to compensate for bigger tires? Is it a mechanical change, or can they do a re-program?



Steve

 

[DSiemens]

The speedometer signal originates at the transfer case on 4x4 trucks. The change will either be a turning of a gear tooth (placement) or installing a gear with more or less teeth.

 

[fullthrottlefarmer]

I had mine changed at the dealer. They can go into the tire size settings with there scan tool and pick the one you have, or they can go in and set the revs per mile deprnding on your tire size. My dealer had a book that listed tire sizes and there revs per mile. My truck is dead on now.

 

[Chipstien]

I was under the impression that on the 24 valves you cannot get larger then 265's unless you use aftermarket calibration boxes. Is this still the case or have they added more sizes to their list of tire sizes.

 

[fullthrottlefarmer]

The only tire size listed on my 98. 5 was 245/75/16. But on there scan tool they can go to tire sizes then there is a option called other and that lets you set your revs per mile. So if you know your revs per mile you can set it. I went to the dealer with what I thought was the revs per mile from a Tire manufactures website and my speedo was off even more with that number than at stock setting, then we looked in a manual they had with tire sizes and rev per mile numbers and it worked. They did not list my exact tire size but if you know the diameter of your tire it will work. Just use the closest match.

 

[elamb]

I talked to the dealer a couple months ago and they told me they could go up two sizes from the 265's. I believe they told me it would cost $60.



Eric

 

[vssman]

what year truck?? Pre 98's use a VSS unit that is located on the driver's side transmission/transfer case. You can change the gear on them to correct the speedometer. 98 & newer use the ABS system to give the computer the road speed and either need to be programmed for what is allowable by the computer or have a separate electronic box added that compensates for the difference in tire size.