Diablosport Forums

Is there anyway I can adjust my speedometer for my gear swap (3.92s to 4.56s with a 35" tire) on my 2003 ram 4x4? I'm using the U7137 with the 9r12 revision.

changing gears will not affect your speedo, changing tire size will though and you can adjust for tire size with the DSP tool on the 2003. the speed is read from an independent sensor that reads a tone ring in the axle and changing gears doesn't throw off speedo readings, changing tire height will for sure though.

just make sure you don't change ratio while installing a tune since some people, not all, have had the DSP wipe their ABS info out during that and this requires a dealer reflash. I had the most success changing tire size from the quick adjust menu.