I have been searching but it seems my google-fu is lacking this week. For some reason after putting on a new set of 31x10.50 my speedo is reading fast. At an indicated 55MPH two different GPS have shown 52.4 to 52.6 MPH, and it just gets worse as I go faster. So, how do you recalibrate the speedo so it reads correctly?

Thanks,
Greg

 

No way that I know besides swapping gears. Have you done that already; if not how did your speedo not read slow before, considering the stock tires size is ~28"? Electronic vss that year?

 

Years ago I knew of a place that would build adapters when you went to over size tires.

With a electronic one it must be possible to modify the signal some how.

Just curious why it bothers you so much??

Much worse if it is the other way.

 

Jet performance makes a speedo recalibrator for these trucks with the electric gauge. I had one but sold it before I had the chance to install it.

 

To recalibrate the speedometer you replace the speedometer driven gear.

Here's an old thread with a lot of detail. http://forum.ih8mud.com/threads/spee...change.480939/

I'm not sure why a different size driven gear will still mesh with the same drive gear, but the poster assures us that it did. (In his excellent photos, the two gears appear to be the same diameter, but have a different number of teeth. Go figure.)

 

Thanks guys, my truck came with 31x10.50 stock that is the reason it bugs me that it is off. The new tires are just a tax smaller than my old ones it seems even though they are marked the same size.

Thanks,
Greg

 

The hack way I did my SR5 speedo was to gently pull the needle of the shaft and reposition it. With the help of a GPS I got it within 1 MPH off at 70. At 35 MPH it still with in 2 MPH. The recent 'SR5 gauge calibration' thread shows were the speedo needle was set. Of course this does nothing about the ODO but I won't get a ticket for that.