Odometer recalibration

[Huskerman]

I need a little advice. The truck I just bought has BFG 285's on it. I believe these trucks come stock with 265's. On my last truck (a piece of junk PSD, but we won't go there!) I had to have the speedo/odometer recalibrated via the ECM to make sure that the speedo, odometer and trip computer worked correctly. This cost me about $95. I would guess that I need to have it done to my new truck but I am wondering if Dodge can/will do it and how much it costs. Ford totally gave me the run-around when I got it done on my Pukerstroker. I actually had to print off a page of instructions from ford-diesel.com to get them to do it!!!



Shawn

 

[CumminsAholic]

I think the dealer can do it now. I'm not positive though. Otherwise I just read (in the new TDR mag I think) that rickson (http://www.ricksontruck.com/) has a new speedo corrector with a one wire hookup, I think that's what I'm going to do someday, for now I rack up less miles. I think it'd be easier just to buy that and be able to calculate for any size tire yourself them have to try to deal with the dealer.

Corey

 

[CBenn]

Superlift has a box called the "Truspeed", most 4x4 shops are selling it for $185. From what I've seen, it splices into the wires coming off the transmission sensor, then modifies the signals going up to the computer. It's adjustable and has a switch for two settings (like if you run 305s around town and 265s when towing).

Hope that helps!

 

[Mschevey]

Our trucks don't get the speed signal from the transmission. It comes from a sensor on the back axle. Just make sure that if you get an "adjustment box" that it will work with the sensor on our trucks.



This is true for the manual trans. 2001 anyhow.



Mike

 

[Mopar-muscle]

the factory can reflash your speedo correction factor , to any size offered by the factory ... if you go to a larger size you are stuck . you have to get a speedo correction device . heres the kicker thopugh , if you have 4 wheel ABS you are screwed still because of the factory the sensor on the rear axle is also the speed sensor for the rear wheel speed for ABS , if you change it and do nothing to the front the ABS think there is a problem ... to date i don't know if this has been figured out , its what keeping me with stock tire size on my ram

 

[work2muchplay2little]

Well here's what I found out when I was looking into this; first you need to figure out which you have just rear anti-lock brakes (RWAL) or 4 wheel anti-lock brakes (FWAL). The difference is that RWAL have just one speed sensor from the rear differential, the FWAL have the one in the rear differential and one from each front wheel. If you have FWAL, you will see both a brake line and cable coming from the front wheel assembly as opposed to just a brake line. Now if you have the RWAL, you can use the Abbott ERA box which is the one I installed. Here is a link for instructions on how: https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=22253&highlight=abbott

If you have the FWAL you have two choices; you can modify the Abbott according to fest3er's instructions: https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=18843&highlight=abbott or you can go with the box Rickson has that is supposed to be set up for FWAL out of the box. Hope this helps.

 

[Huskerman]

Odometer recalibration...UPDATE

I took the truck in today and had the dealer I bought it from recalibrate the odometer. They had it done in under 10 minutes and I was told it was a simple computer adjustment. Best of all, they didn't charge me anything. The service guy said that they couldn't match my 285's exactly but that it would be a lot closer than it was. His exact words were "we can only adjust it specifically for the tire options from the factory; 245 & 265. The next setting up is "OTHER". " I have only delt with this guy twice but he seems to be a straight shooter, so I believe him. Of course I have been burned before.



One thing I wanted to mention was that the reason I wanted it recalibrated was not only so that my trip computer would be more accurate but also because of a problem I think I am having with the cruise control. At speeds between 55 and 60 mph, the cruise control is constantly speeding up and slowing down. At all other speeds it is very stable and only adjusts the speed ocassionally. I am not a mechanic by any means so maybe the tire size has absolutely nothing to do with cruise, just a guess on my part with the way everything is computer controlled now a days. I know on the FORD SuperCrappy that I had before this truck, I was told via multiple sources that tire size had an affect on the auto transmission due to calculations the computer made. Maybe I am just an idiot, I am sure somebody here will set me straight.



Shawn

 

[StakeMan]

I recently installed a superlift tru-speed box on my truck. It ties into a wire at the abs controller. I used a gps to calibrate. seems to work good.