I always see 4.56 gears on here....my dumb question is this....[:'(] are these 4.56 gears for the transmission, or differential? I am thinking difff, it'd have to be....so what exactly is different between the 4.56's and my current 3.92 (or whatever it is?) and how much does this cost TOTAL to buy and install? and what are the benefits/cons? thanks!

 

There are no dumb questions. The gears go in the differential. I'd love to know how much it would cost, too. The lower the gear ratio (higher number), the quicker you are off the line. For example, 4.56 gears will get you going quicker but will limit your top end. You'll also lose fuel mileage with the lower (higher number) gears. I hope this makes sense.

 

Yep.............your right Monkeyman to a certain extent.
People who have Rams with 20" wheels and above, or with huge tires such as Iroks/swampers etc, change to 4:56 gears from say 3.55's and actually save on mileage. That's one of the main reasons for the change. That, and it also gives back a little of the performance lost, due to putting on these huge wheel/tire combo's, due primarily to their larger diameters, giving an effective drop in gear ratio and their heavier weight.
The reasoning behind this, is that it's easier to get the mass of the truck rolling and keep it rolling with the 4:56's, due to an increase in mechanical advantage of the gears.
You are correct however, that if you increase the ratio even futher, you would eventually see a decline in MPG.
There is a formula out there somewhere that you can use to get the "perfect" gear ratio given the tire/wheel combo' and what style of driving you do. Apparently, changing to 4:56's if you drive mostly the street/urban type cycle, will usually give an increase in MPG.........if you can keep your foot out of it that is, cos' I heard that lighting em'up is a real fun option once these gears are fitted ha ha ha.
Al.
Soon to be a 4:56 geared detroit/auburn assisted LPG/petrol Hemi powered beast in the UK ha ha ha.

 

The gears will do what was said, except, they will not limit your top end enough to even think about.

Gear sets go for around $200 and install kits (recommended by good shops) go for around $100. Install for the rear is around $300 around here. Install for my fronts was more like $500 because they have to remove the whole dang assembly from the truck to work on it.

If you have 4X4, you'll need both sets.