Engine/Transmission (1998.5 - 2002) Speedometer correction completed by dealer

[dieselshu]

Well I took the truck into the dealer today and had them reprogram for 285's cost was $42. 00 and I was out in 30 minutes. They could not pull the tire size up on the scanner, it only went to 265's, but they where able to put in the rpm of 634 under ABS section other. I checked the speed against my handheld Garmin GPS and it was dead on accurate.



Dave

 

[madmax4688]

Your lucky it took me and my cousin (who works for dodge as a mech) over 45 minutes and 12 reprograms to get the speedo accurate for my 315's. I knew it was off when every radar on the highway said I was going 75 and the speedo said 62.

 

[MattSt]

Your lucky it took me and my cousin (who works for dodge as a mech) over 45 minutes and 12 reprograms to get the speedo accurate for my 315's. I knew it was off when every radar on the highway said I was going 75 and the speedo said 62.

Can you post what you changed? I'm going to try and take mine into the dealer to have my speedo fixed for the 315's I just put on. I'd like to just be able to tell them what to do and not let them try and figure it out. :-laf



Thanks

 

[TSRAM]

Bump... ... ... .....

 

[Beast2B]

Just as Dave said, you can input the rotations per mile instead of the tire size. Factory only offered 245/75-16 and 265/75-16 in the pre-programmed options, but input 600rpm for a 315/75-16 and you'll be REAL close. (BFGoodrich has rpm listed in their specs, other brands may also. All-Terrain says 601rpm, Mud-Terrain says 598rpm)

 

[EricBu12]

I use the Superlift Tru-speed Correction box



http://www.superlift.com/products/misc/truspeed.asp



It has 2 positions for different tires you have for like winter and such... . Each position has it own dash-pot adjuster so you dial it in to get it close, then use Mile markers and the trip odometer on your truck to adjust it faster or slower. Turn the screw one way, the speedo goes faster, turn the other way, it slows down... . Took a few miles at a time on a deserted road to do mine with the 245 70R 19. 5" tires I have,. . but got it within 100' off in 13 miles... . That is on the #2 position



I have the original 16" Michelin tires for the winter (the coated rims... ) and that tire is on the #1 position so when winter comes, I switch tires and then flip the switch on the box and the calibration is set for those on that position. Only a 4 wire hookup under the hood by the fender. Took 15 minutes to install and 2 hours to adjust.

 

[DMannon]

New url for the TruSpeed:



http://www.superlift.com/accessories/truspeed.asp