How do you know what gears you have? I bought my truck used and don't know what it had stock or if the previous owner changed anything. I have the towing package if that matters. And it's a 4X4 Hemi.

 

There will be a little white sticker wrapped around the axle, under the truck. It will be over on the passenger side. It will say what is in it. That or take your VIN to the dealer and they can tell you.

 

or check the sticker in the glove box

 

what they said is true but if the previous owner changed it then the stickers would be incorrect. i would have asked before i bought it but most ppl would advertise that they changed the gears when selling so if he didnt say anything about it then you could bet its stock. if youre still not sure then you could call him and ask him.

 

First off, the only stupid question is the one you don't ask. How the hell else are you gonna learn anything?

Jack up both rear tires and put the truck into neutral.

Put a mark on the driveshaft so that you can watch and count the number or rotations it makes in the next step.

Put a mark on one of the tires.

Rotate the tire one full turn and count the number of times the driveshaft rotates.

It if rotates once, then you have a 1.00 rear. If it rotates around 3.5 times, its a 3.55, and so on.