Engine/Transmission (1994 - 1998) 98 12valve speedo

[CodySanders]

my question is do i have a electronic sending unit that can be changed by a computer or is it a gear that needs to be changed? thanks

 

[fest3er]

my question is do i have a electronic sending unit that can be changed by a computer or is it a gear that needs to be changed? thanks

The 98's all use the rear diff sensor, which feeds into the CAB. The CAB can be programmed for a variety of tire sizes. The best device to calibrate the speedo/odo is the Tru-Speed box. I've been using one for some years now; the speedo and odo are dead-nuts on (within 1% or so). Drive 100 marker miles; get the ratio of that to the odo reading. Adjust the Tru-Speed by that amount. You should then be within 1% of true.

 

[CodySanders]

thanks for the info that answers my question

 

[CumminsPower98]

I really like my Tru-Speed box. It has a two position switch so it can be setup for two tire sizes. I run two sizes so this comes in very handy. All I have to do is flip the switch and I'm all setup for the other tires. If you run only one size all the time the dealer can make the adjustment. I really like the flexibility of the box though.