Manual locking hubs are located on the front axle of a 4WD vehicle. They are the small dials found in the middle of the two front wheels. On the outside, they appear simple, but on the inside they perform something extraordinary.

When driving your 4WD vehicle on a slippery, icy, or muddy road, you may care for little else except that each tire has power and is fighting for every bit of traction. When four wheel drive is not in use, the locking hubs are used to disconnect the front wheels from the front axle drive components (differential, half-shafts, and driveshaft). Doing this will allow the front axle drive components to stop spinning, saving unnecessary wear and tear on those parts and helping to improve the fuel economy.

Manual locking hubs were invented by Arthur Warn in 1948. Until then, the typical 4WD vehicle was “full-time” 4WD. These were undesirable because the constant 4WD made them suffer from excess wear and stress on all the drivetrain components from the front axle to the rear axle and everything in between, poor gas mileage, and bad street driving characteristics especially on dry pavement.

Over the years, most 4WD auto makers have done away with manual hubs and made a switch to automatic hubs. The SUV craze that took the American auto marketplace by storm in the late 1980’s and well into the 1990’s is likely responsible for this. Families from all walks of life had to have an SUV because an SUV meant 4WD. The problem was that an overwhelming majority of these SUV drivers wouldn’t know how to engage the 4WD system. To make the SUV more appealing, manufacturers outfitted them with automatic hubs.

As years went by, 4WD owners (especially off-roaders) have learned that automatic hubs aren’t the wonderful amenities that the auto manufacturers made them out to be. As the vehicle aged, the likelihood that the auto hubs would work when needed diminished. It’s a rule of engineering that when you take something simple and then complicate it, the chances for failure increases. Automatic hubs were no exception to this. Auto hubs are notorious for not working at critical times and for being weak under stress. Ask any off-roader about this and you may get an earfull of anger and bitterness toward the auto hub.

Manual locking hubs are stronger than their auto counterparts. It’s for this reason that off-roaders will always choose manual hubs over automatic ones. Even if an axle with automatic hubs has been routinely maintained, the serious off-roader can not rely on it because there are too many circumstances for which it will fail or just not perform when the moment is critical.

Manual locking hubs feature simplicity, reliability, strength, and low cost which has made them the ideal replacement for auto hub axles. There are kits available in the off-road marketplace that allow drivers to replace automatic locking hubs for manual ones.

Understanding how these units work will help you get the most out of them and they are much easier to upgrade and maintain than auto units.