An upgraded Jeep design with sturdy inner knuckles can be all that you need to unlock a new level of amazing off-road experience. Of course, we are pretty sure you aren't planning on slamming the undercarriage of your vehicle against a boulder. Still, it's never a bad idea to be prepared for all circumstances, especially as you never can tell what might come up on the trail.

How do you even know which is which among the wide array of genuine Jeep axles and cheap knockoffs that have flooded the market today? Here is how:

A Jeep Wrangler's axles are a popular swap project. Sometimes it's an upgrade, and other times it's because you destroyed your current axles in the last trail run and you need to replace them. When it comes around to replacing an axle, you will need to know what you have and what you will be replacing.


For reference, we're not just talking about axles. We're talking about differentials. Technically, the axle is the shaft that connects to the wheel and rotates with the gearing inside the differential. For instance, here is a typical example of a rear axle made by Omix for a Dana 35, Part 5012820AA. Note the studs at one end to bolt the wheel on. The Omix part is more of a kit and includes a new axle bearing and seal. For the most part, visually, all axles look about the same in a photograph. However, the lengths, thickness, size, and spline count will differ from axle to axle. The differential housing has two axles (a left and a right). Typically they are about the same, except the length can be different (but on some vehicles, they can be the same exact part, left and right). Jeep has used a variety of differentials over the years, and they can look almost the same. But since you can buy the entire housing or even a complete differential setup, it's easy to see the differences once you take a closer look.


Dana 30 differentials are used in most Jeeps. From the CJ-series (CJ5, CJ7, CJ8 Scrambler) to the YJ, TJ Wranglers, and even XJ Cherokees. These axles would be made for open-end steering, meaning they allow for front spindles and parts that will enable the vehicle to turn. They have 10 bolts on the cover plate. The stock shafts typically have 27 splines (though you can count yours to verify, of course). Here above is a picture of a cover from ARB, Part ARB-0750002B. Notice it has ten holes (the one larger hole near the bottom is to drain the housing of oil without moving the cover). To get an idea of the whole differential end to end, here's a TeraFlex Tera 30 Heavy Duty Front Replacement Axle Housing (Part TF-3503004). Note how the ends are made to accept spindles.


The Dana 44 has been used on the front and rear of Jeeps. Over the years, they've become more common on the rear than the front. Except for some interior components and other obvious minor differences on the outside with brackets and such, they are almost the same. The fronts have the changes needed for spindles, while the rear ones allow for the axles to accept bolt-on wheels. Here's a Dana 44 front differential below, a G2 Front Dana 44 Assembly, Part D44TJFA456. Note the way the ends are made for spindles.
Here's a front Dana 44 cover from Rancho, an RS-6209. The Dana 44s have 10 bolt holes. The large bolt hole on this style is for filling the differential with oil. Here is a cover for a rear Dana 44 by Spicer. Part SPC-42960-1.

In some cases, the cover will fit front and rear, depending on the manufacturer. For comparison, here is a rear MOPAR Dana 44 Assembly, Part P5153826AB-M. At this point, we've covered some of the popular and more common differentials that were stock on Jeeps. There are some others, like the front Dana 25 or 27's, used on older Jeeps, 1986 and older, back to the 1941 Willys. There's also the AMC Model 20 rear differentials that were used during the time when AMC owned Jeep, around 1976 to 1986. If you would like to see blow-up parts diagrams of all the smaller parts inside a differential, we have those broken down by the different models to make them easy to see and order parts from.


When modifying a Jeep, the Dana 60 is popular for racing and serious off-roading. While it's not a stock option in the Wrangler family, they are used on 3/4 and 1-ton pickup trucks. Not to mention drag racing where torque can be devastating on lesser differentials. Here is a rear Spicer Dana 60 Crate differential Assembly we carry, Part SPC-2018444-2. That one is essentially made to the right size and length to bolt up to your JK Wrangler. Fortunately, Jeep hasn't used too many different differentials, so figuring out which one you have isn't a big deal. Here at Morris 4x4 Center, we carry the parts for just about all of them to keep you on the road and trailing for years to come.

Even if you would like to take your drivetrain upgrade a bit further, you can count on our extensive list of Jeep axles from about 45 top brands in the business.

What kind of axles do you have, and what type of driving are you doing?