I have the same problem. My calibration is way off and I have no more calibration tries. From what I know from here and Ford you have two options. Send the cluster to a speedometer shop and have them repair or reprogram whatever they do, or replace the cluster. Fordparts.com sells clusters for about $270. Someone like LMC may be cheaper. I emailed tacoma speedometer about mine and they said they would reprogram mine with 6 tries and set at my calibration, replace my cracked bezel, for around $130. Your mileage is on a seperate chip, so you just unplug it then plug it back in, does not change. I think you could just replace the speedometer with one from a wreck too, but I'm not sure. That would probably be the best if you could, because the speedometer is the same for gas or diesel, manual or auto, so they should be everywhere in boneyards.