Is there a chart that shows what speedo gear to put in my 2005 Ram 2500 4x4 Quad Cab if I change tire sizes?

I have 265/70/17 now, which is stock. I may change to 'Power Wagon' size 285/70/17. I was going to order the speedo gear from the power wagon, but now I think that maybe my axle ratios may be different. Does that matter?

Any advice on how to figure out the proper speedo gear?

Thanks!

Derek

 

There is no gear to change. You have to reprogram the PCM to the tire size. You can either buy a tuner such as a Diablosport Predator or a SCT. Your dealer can do this as well, but may or may not charge 1hr labor to do so. The speedo is driven by the speed sensor in the rearend.

 

Don't even waste you time. Going to a 285's won't make much of a difference.

 

True enough. I went from 265s to 285s. Speedo went from pretty much dead on to an indicated 76 = 80. If you have a GPS, it's a more accurate speedometer anyway.

 

They stopped using plastic gears in the tailshaft housing years ago. Like was mentioned, its all computers.

 

Hi,

i have the same problem for my dodge 3500 99' i changed my wheel for 22.5!

can i fing a speedometer gear replacement some where?



THANKS

Claude

 

Not sure if 99 is the same as the 02-up, but if so, you need to have the dealer reprogram the pcm or buy a tuner and do it yourself.