so we changed our gearing..went from 3.55 to 4.10..now the speedo is off about 10mph...65 mph reads 77 mph on the speedo...anyone know where to get the adapter or whatever its called to mount on the tranny.....i am assumming that this is what is needed to be done...and would it be one with more teeth or less teeth...yes i am confused...thanks...1996 ram 1500 5.9l

 

I think its PCM controlled. Call your dealer or get borrow a programmer.

 

i can never remember the cutoff years for which is which, but the later years have a speed sensor in the top of the rear diff, which reads the tone ring on the ring gear, which is independent of the gearing. so in these, the only variable is tire diameter, not gears, and its is computer controlled. you should be able to identify this setup by the electrical connector at the top of the rear diff. if you have this, and you have STOCK tires and wheels, and your speedo is off due to gears only, then i'm confused... gears only should not affect speedo.

if you have this, do you have stock sized tires/wheels ?

if you don't have the electrical connector on the rear diff, then you have the gear in the speedo, which (at least on my old chevy) was easily changeable, just change it to +/- one tooth.

edit - computer control is on the 46re trans. gear control is in the 46rh.