Engine/Transmission (1998.5 - 2002) Speedo Calibration

[dwmobz]

Just put 285 16 tires on my 98. 5 Auto 4x4. Speedo is off about 7. 4% (hey I'm an engineer). Been to a transmission shop who tried to reprogram the computer to compensate but no luck. The computer gave three choices Goodyear or Mich. (both 245's) or other. But the other option did not allow input of alt sizes etc. Two dealers told me they can't do it. I can't believe there is no straight forward way to re-cal. Is there an aftermarket solution? Would a rear end shop be able to help?

 

[badams1]

speedo options

I just went through a gear ratio change and found out that the speedometer is set by the tire/wheel rotation sensor on my 2001. 2 2500. The dealer had three tire size options for my truck but nothing for gear ratio. So you are probably stuck with those options. But hey! where there is a will there is a way. You my have stumble on the mother of an invention, being an ENGINEER!

Wild Bill

 

[kaffine krazed]

I found a company selling a box that changes the frequency of the speed sensor. I'm sure there are other companies selling simaliar products.



http://www.atrol.com/cx_era.htm

 

[JR2]

Hey guys check out this thread www.turbodieselregister.com/forums/showthread.php?s=&threadid=48648&highlight=Abbot



There are basically two well know boxes guys on here use. One is the Abbot and the other is the skyjacker truspeed. If you have 4 wheel ABS you need an Abbot from Rickson tires (modified by them) or a truspeed. There is also a lnk to the abbot mods for 4 wheel abs in the link I posted.



By the way this site has a fairly good search utility, if you look in the upper right hand area there is a search button. Typing in Speedo Correction you would find these results .



Good luck with the correction, I will be doing it soon too as I am going to get bigger tires and change to a 4. 10 gears.