Brock227

I'm looking at lower diff gears, just curious on the whole speedo side of things... From what I can see the speed sensors are on the hubs so this would mean that it wouldn't change the speed only the revs as opposed to a car thy would read the speed from the drive shaft? So no adjustment needed?

Billman250

Road speed is read from the transmission, not the wheels.

So you will need a yellow box to re-calibrate the speedo to match your actual road speed.

Or just leave it alone, as it will be reading faster and you will get less speeding tickets

Brock227

Okay that would require calibrating it with a computer I assume? Also billman, since you're the go to guy, I got a bit of a worrying noise, If you wouldn't mine helping me figure out what it is?

S2KPUDDYDAD

The yellow box is a little device you wire into the ECU to change the speed read by the speed sensor on the trans. You can install it and dial it in your self pretty easy at a cost of bout $70

Brock227

So the adjustment dials are on the box? Where would be the best place to buy one from?

Billman250

Modifry.com sells a device. For your noise, a thread with a sound clip is the way to go.