Speedometer calibration after lift/tires

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DWs-TTEB

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Thanks for the updates, this gives me hope, but I'm still a little confused. It sounds like you added a custom tune and then used forscan to relearn/reset the TCM in order to get rid of the wrench for 35's (I think your tires are 33s though). Is the right? I'm not seeing anyone else w/ success on tires greater than 33's. I have 35's (285/75R18) and have a Hypertech Programmer/Tuner (Part #3050) on order. Should I expect to need to get a forscan as well after updating tire size via the tuner? Or should the tune just work? I assume I'm going to have to deal with an incorrect speedometer and gearing...



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My tires are 33” off the truck & 32” on the truck. Most aftermarket tuners allow you to adjust the tire size. However, I’m not sure about the tuner you bought for this model. I know Forscan will all you to mod the tire size. A custom tune from say 5Star or ZFG etc. will do it as long as you tell them your current mods. ForScan allows you to have the vehicle relearn the tire size axle ratios etc. with the ECM/TCM relearn function. The ForScan OBDII reader cost $15 on Amazon and the ForScan license cost $10. YMMV.
 

Aaadd0826

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I recently installed the Readylift 3/2 lift along with the recommended 285/75r18 tires on factory wheels. Those tires are actually a little too big and were rubbing in the rear before doing some trimming of the liner. The fronts just barely clear, and rub slightly in the right circumstances. I should've went smaller actually, and I wasn't too impressed with the recommendation and instructions from Readylift. I did achieve the clearance I was looking for though.

Now the problem . . .

After installing the tires I planned on adjusting the tire size through Forscan as I successfully did on my F250. I assumed I would be able to go up a little bit on tire size without issues, but I found that any value I put in other than the value for the factory size tires would cause wrench icon to appear in the dash. I went back and forth several times until I found the right value to accurately calibrate my speedometer to the bigger tires, but now even if I change the values back to stock the warning won't go away.

Has anybody found a successful way to calibrate after installing bigger tires without a DTC? And apparently there is not a range of sizes to work within without throwing a code like in the pickups?

Thanks!

View attachment 30718 View attachment 30719 View attachment 30720 View attachment 30721
I have 285/75r18 on mine with little trimming
 
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