Speedo Correction

[KWentling]

After wearing out the original Goodyears (52,000 miles) I have put Michelin LTX 235/85/16E M&S on the truck. I stopped by the Dodge dealer to have the computer flashed to compensate for the size change. They put the DRBIII on it and the only options shown for tires were either Goodyear or Michelin and only in 245s.

I understood from this forum that others have had this changed succesfully. The tech said some have that option and some don't. Mine doesn't. So. Is this the case or do the techs not know how to do this. It seems to me that what DRBIII was showing was the tire combinations that were original equipment on the truck, not sizes that it could be flashed to. Anybody else run into this? I checked the speedometer with my GPS and it is off only by 5 MPH at 75. I can deal with it for now, but I would like it to read correctly for the odometer reading, and simplicity for the other (better?) half! I can go the Abbott (sp?) route if necessary. Where does one buy on of those?

Kim

 

[Bigramguy]

I think it is the newer trucks that have more programabilty,so you can input the rev\mile of the tire. I'm not sure what they used on the early 98 12V for the speedo. If it is like some of the earlier trucks,you can get different speedo gears to compensate. If it is the newer style,then you would use something like the abbott. I'm sure someone will chime in with the correct info.

 

[CumminsPower98]

I have a '98 12 valve and in '98 the speedo was changed from the gear drive on the transfer case to an eletrical signal from the ABS sensor in the rear diff. I installed 33" tires so my speedo is way slow. I just perchased a Superlift Tru-Speed speedo correction box which I hope to install this weekend. I will know how it works after that. I have heard that others have had good luck with this unit so I am hoping it works out for me. I called a dealer near me before buying the unit and they told me they could only correct for factory certified tire sizes, go figure. Anyway I will try to let you know how it works out if I can remember.