Hi, guys, I recently upgraded to abrand new set of dick cepek FC's II in a 315/75-16 size.

Does anyone know how to recalibrate the speedometer?

I heard about changing the gear on the speed sensor located atthe t-case to a larger number of teeth on it. Can anyone help me know how many teeths shoul be in order to get the speed corrected.

Any help is welcomed...

 

The speedo is digitally controlled. The rear end (or transmission, whichever the case may be) sensor sends so many signals per turn of the axle. The PCM multiplies the number by the programmed tire size tho figure the speed. Sorry dude, you need it programmed. I'm in the same boat 'cause I replaced my 265s with 285s. You now have three options: one, live with it and learn to figure it in yor head. Two, go to the dealership and have them to fix it (around $100). Three, buy a reprogrammer with that capability (around $350). I'm going with the latter 'cause you get more power, and you can reprogram multiple times....

 

i had replaced the stock 275 on the 16inch with 265. i now have 275 tires on 20". since my tire size is now the same as the 275 that came with the truck, should my speedo still be bang on?

 

on a 96 its still gear on the speedo , so the PCM does not have full control over it , started in 97 on up..


nmason , you should be damn close to the right speed , so no change is required , by default speedo are off about 5 mph..