Manual Locking Hubs
Buyer's Guide by Axle and Spline

Manual locking hubs are one of the simplest parts on a 4x4 and one of the most ordered wrong. The fitment depends on the front axle, the axle shaft spline count, and on some trucks whether it is single or dual rear wheel. Vehicle year alone is not enough, because front axles got swapped, upgraded and regeared on a lot of these trucks long before you bought them.

Here is how we tell people to buy hubs, and where the money is worth spending.

Step 1: Identify the Front Axle

Look for the tag on the differential cover bolts or the casting numbers on the housing. Dana 30, Dana 44 and Dana 60 are the common solid front axles on older trucks and Jeeps, and the GM 8.5 inch shows up on older GM K-series. Our axle guides cover the Dana 30, Dana 44 and Dana 60 if you need to confirm what you have.

Step 2: Count the Splines

Pull the hub cap or the existing hub and count the splines on the outer stub shaft. This is the number that decides fit:

• 19 spline: common on Dana 44 and GM 8.5 front axles in half-ton and three-quarter-ton trucks.
• 30 spline: found on some Dana 44 and Dana 30 builds with upgraded shafts, and on many Dana 60s.
• 35 spline: heavier Dana 60 builds, including the 1999-2004 Ford Super Duty Dana 60.

If someone has put aftermarket chromoly shafts in the axle, the spline count may not match what the factory used. Count it yourself.

Stock-Style vs. Heavy-Duty Hubs

Stock-style replacement hubs

For a daily driver or a work truck that sees snow, mud and the occasional two-track, a quality stock-style hub is the right buy. On a Ford Super Duty, the Super Duty manual locking hub pair or a single Super Duty manual hub puts it back to factory function without spending more than you need to.

Heavy-duty hubs

Big tires, lockers, and real rock or mud use are where stock hubs break. The weak spots are usually the inner drive gear and the dial assembly. Heavy-duty hubs use stronger internals and a beefier housing. We carry heavy-duty sets for the common applications:

• Dana 44, GM and Ford half and three-quarter ton, 19 spline
• GM 8.5 front and Dana 44, 19 spline
• Dana 30 and Dana 44, 30 spline
• Dana 60, 30 spline, older Dodge, GM and Ford
• Dana 60, 35 spline, older GM, Ford and Dodge
• 1999-2004 Ford Super Duty Dana 60, 35 spline

Our honest take: if you are on stock-size tires and an open front diff, a heavy-duty hub is money you could spend elsewhere. Once you are on 35s or bigger with a front locker, the stock hub is the next thing to break, and it always breaks at the worst time.

Spin-Free Conversions

Many newer trucks and Jeeps have unit-bearing front axles with no hubs at all. The front axle shafts, front diff and front driveshaft turn all the time in 2WD. That costs a little mileage and puts wear on parts that are not doing anything. A spin-free conversion replaces the unit bearings with a hub setup so you can unlock the front end.

These are big kits and they are not cheap. We stock conversions for the Jeep TJ, XJ and YJ Dana 30 and Dana 44, the 2000-2008 Dodge single rear wheel, the 2000-2008 Dodge dual rear wheel, and the 2012-2015 Ram 2500 and 3500. They make the most sense on a truck that spends most of its life in 2WD on the highway, or one that is already due for unit bearings.

Install Notes That Save You a Second Trip

• Clean the axle shaft splines and check them for twist or wear. A new hub on a worn shaft will slip.
• Set wheel bearing preload correctly before installing the hub. Hubs do not fix loose bearings.
• Use the correct grease sparingly inside the hub. Packing it full makes the clutch slow to engage in cold weather.
• Replace the hub O-rings and gaskets. Water in a hub rusts the internals fast.
• Lock and unlock both hubs and turn each tire by hand before you drive. A bind means something is assembled wrong.

Signs Your Hubs Are Due

Hubs rarely fail all at once. They give warnings, and most of them show up months before a hub actually lets go:

• The dial is stiff or gritty. That is usually water and rust inside. It will get worse, and a hub that is hard to turn is one somebody eventually forces and breaks.
• Clicking from one wheel in 4WD. The engagement teeth are worn and skipping under load. Each skip rounds them off more.
• One side engages, the other does not. With an open front diff, that means no front traction at all. Do the jack-stand test in our hubs not engaging guide to confirm which side.
• Grease on the inside of the wheel. A failed hub seal or O-ring lets grease out and water in.
• Cracked or chipped housing. On aluminum-body hubs this happens after a hard hit. Replace it. A cracked housing lets the internals shift.

If you catch it at the stiff-dial stage, a clean-out and new seals sometimes buys time. Once the teeth are worn or the housing is cracked, replace the pair. Hubs are cheap compared to a broken axle shaft from a hub that let go under load.

FAQ

Can I mix one new hub and one old hub?

You can, but if one failed from wear the other is probably close. On a truck that sees real 4WD use, replace them as a pair.

Do manual hubs improve fuel mileage?

Slightly, compared to a front end that spins all the time. The bigger benefit is less wear on the front diff, shafts and front driveshaft in 2WD.

Will heavy-duty hubs fix a front end that does not engage?

Only if the old hubs are the problem. Check the transfer case, front axle actuator and shafts first. See our guide on locking hubs not engaging.

What spline count are Ford Super Duty hubs?

The 1999-2004 Super Duty Dana 60 uses 35 spline. Later trucks and different axles vary, so count your shaft or match the part number on the old hub.