I've been looking for an '06 2500 Diesel, and usually ask what axle gearset the truck has. I'm ost often met with a quizzical look. So I have 2 questions: is there any way to determine what the axle ratio is just looking at the truck when no other documentation is available? and 2.) what determines what axle ratio the truck has...is this a factory thing or was it ordered with whatever is in it (maybe the GVWR?) Thanks for making me just a little less dumber than I normally am.

 

My 95 had a tag on the diff, i got a printout from the dealer for my 07.

 

You can get a spec sheet based of your VIN from the dealer. You also could look in the glovebox. If all of that fails you can get under the truck and jack the rear axle off the ground, put it in Nuetral and use a peice of chalk to mark the drive shaft and the bottom of the tires, then turn the tires. If the drive shaft turns 3 1/2 times to the one turn of the tire, then you have about a 3.55 gear. If the shaft turns almost 4 times per one tire rotation then you have a 3.92 gear.

 

What weedahoe said ^^

95% of the time, the axle ratio is listed on a sticker in the glovebox, or on the axle. If not, you can run the VIN through Dodge and get a build sheet that will have it on there. There are also a few websites with widgets to determine what gears you have by entering engine RPM, speed, tire size, and transmission info and it will do the math to figure out your gear ratio.

 

pyro said ho lol...

but ya tag in box most of the time

 

Thanks for the help guys, I'll start checking the glove box. The spec sheet idea won't work though. I did query Dodge for a build sheet on one truck i was looking at, and they only provide that to registered owners due to privacy concerns....damn if I understand what's so private about the equipment a truck has, tho. Regardless, thanks for the input.

 

Diesels start with a 3.73 and go up (numerically) from there, right? I don't know how many different ones there are.

 

count how many rotations of the tire it takes for the driveshaft to go around once. or any of the other methods listed
or is it the other way around one rotation of tire for how many driveshaft idk