Tech Corner: When to Consider 4×4 Axle Upgrades

Tech Corner - IntermediateUpgrading 4×4 axles is something every off-roader is going to consider at one point or another. The axle assemblies are on the front line of the abuse and obstacles that every four-wheeler is going to face. Whether it’s for traction, durability, or to get those bigger wheels and tires up to speed, axle upgrades are an extremely common modification.

First things first, settle on a purpose before you launch your game plan. It’s best to take into consideration what the intended use of the vehicle is and what upgrades will be made aside from the axles. For instance, if it’s a truck with bigger tires on it that will be driven on the street, ring gear upgrades might want to be discussed. Something with an intermediate level of off-road use may warrant a ring gear upgrade along with some carrier work, while all out off-road monsters may need an overhaul of everything or just a whole new axle assembly to keep up with the abuse. But before we dive into the areas that can be upgraded on a differential, let’s establish a baseline.

Identify your Equipment for Proper Axle Upgrades

Knowing and understanding the differential in a truck is the key to knowing what upgrades you should consider. You might jump under the rig, run the ID Tag, and find that the axle itself may be something already very durable but with a less-than-perfect carrier inside or a small ring gear.

Research how to identify your axle type so that your project doesn’t end before it even begins. Once you know exactly what is under your ride, you can begin considering what axle upgrades are right for you.


The carrier is the heart of the axle assembly. This defines the traction characteristics of the vehicle. And even if it won’t see an upgrade, it’s important to understand the type of carrier you have in order to make for a good driving experience. What are the benefits of moving from an open diff to a limited slip? How about a spool? Should you run a locker? It’s important to consider when each type of carrier is appropriate and why. Research your options and reach out to members of the off-road community for some friendly advice.

Our thoughts? For all trucks, if you have an open differential you’ll probably want to go ahead and swap in a limited slip unit. Open differentials only send power to the tire with the least amount of resistance in low traction situations. Limited slip differentials do the opposite, but can still send power to both tires with more going to the side with traction. Spools or locked differentials are good options for vehicles that will be mudding or crawling, as both tires receive 100 percent of the power at all times. But that increased articulation isn’t great for street use or turning in general. Locker-style rears can be used in their place, though. Lockers are usually open differentials that can be locked up on demand in case you require both tires to receive all the power from the engine.

Ring and Pinion

Ring gear upgrades are one of the most common axle upgrades. In most cases, if not all, ring gear upgrades will be made to the truck if it is being suited up for off-road use. Bigger tires will take more torque to spin and a vehicle with bigger tires will feel a bit sluggish with the factory ring gear. Lower gear ratios make it easier for the engine to get the tires up to speed. This means the vehicle will be much more responsive at lower engine speeds. This is ideal for the low speed situations that are very common off-road. You won’t have to wind your engine out as much to get the tires moving and this is why most, if not all, trucks can benefit from moving to lower ring gears.

You want to make sure that you pick out a good ring gear, like one offered by a brand such as Yukon or Richmond Gear. These units are under high amounts of stress at all times and you want to make sure the materials will withstand the test. Installation of these units shouldn’t be tackled at home, unless you have the proper equipment. We’ll touch more on installing axle upgrades in our second part of this series (So stay tuned!) but, remember, there’s nothing wrong with having a professional do the work within an axle.

Axle shafts

No one wants to snap an axle shaft when they’re out wheelin’, and this is an area that should be upgraded when serious abuse is in mind. As you build up power, add lower gear ratios, and even a better carrier, the axles are facing more and more hard work. The axles are the shafts that run from your carrier out to the wheel. As the differential spins the axle, it’s working against the traction of the tires to move your truck.

In most cases, intermediate level off-roaders or street trucks really don’t need upgraded axles as the abuse they see is quite moderate. If, however, you plan on driving hard often, with a hopped up engine and a locker diff, you’ll want to take a look at beefier axle shafts. For this, turn your attention to someone like Dana Spicer whose been in the game for a long time. When it comes to something like an axle, you really don’t want to skimp and go with cheap materials.

Full Assemblies

So, you might pop under your truck and find a runt of a differential. Something that has a small ring gear, an open diff, tooth pick shafts, and is likely going to explode when hammered off road. Now’s the time to consider upgrading to a full axle assembly.

Yes, this job is very costly. The best way to save yourself some money is to be realistic about your intended use of the vehicle. If you plan on driving around on the street more often that off it, you’d be better off just building up factory equipment. The more hardcore guys, who will abuse that diff and eventually break it, already know this has their name all over it.

You have two options in this department. You can scour the classifieds and the junkyard for a decent Dana unit, or you can purchase a brand new one from G2 Axle and Gear. If you choose to save some money and buy one used, keep in mind that you may need machine work done and will likely be gutting it and replacing the parts inside anyway. Brand new units can be ordered vehicle-specific with everything ready to go.

We know the best part of any upgrade is actually getting to see the final results, but good mods mean good planning. So, do your homework and get some advice from fellow off-roaders and the pros. Then check back with us for Part 2 where we break down the different areas of focus when installing those axle upgrades, and whether it’s a job you can take on yourself—or one you should leave to the pros.

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