A couple of decades ago, vehicles were designed for a specific purpose and were not meant to be multi-functional. In other words, a saloon car was supposed to carry your family from point-to-point, a pickup truck was designed for a trades-person and there was no such thing as an SUV. Much has changed since then, and this has led to the proliferation of crossover vehicles. This quest for variety has led to the development of one specific transmission component that could be problematic for everyday drivers — the locking hub. Could this be an unknown problem for you?
Demand for Variety
This type of hub is fitted to a large number of sport utility vehicles as an integral part of their transmission and is designed to switch off traction to two out of the four wheels during everyday driving. In other words, the manufacturers know that most Australians use these vehicles on unsealed surfaces and may never venture onto a loose road and have introduced the locking hub to cope with this variable demand.
How This Works
When this type of hub is engaged, the wheels on that axle will not receive any power from the engine. In this mode, they will freewheel just as if the vehicle was a conventional, two-wheel drive car and this will prevent excessive wear and tear. The driver should also be able to return a higher rate of fuel efficiency.
In the old days, this type of technology was manual, which meant that you had to engage the hub by crawling underneath the vehicle. These days it is meant to be automatic and should work whenever you engage the stick within the passenger compartment, but as with everything else, it can occasionally go wrong.
You may notice an odd sound whenever you are trying to manually shift from all-wheel drive to basic mode. Even though this could be an issue with the transfer case, it's more likely a sign that the locking hubs are not working. You may also notice a drumming noise when you're driving down the road if the hub has not disengaged correctly, and if left as is, this would lead to increased tyre wear.
How to Check
You can tell if the locking hub is working by lifting the side of the vehicle up with a trolley jack, when the vehicle is in two-wheel drive mode. Try to turn the front wheel by hand and it should move quite easily, but if it's still locked to the axle, then the shafts will move at the same time.
Are You Affected?
Sometimes this problem can go unnoticed and you may wonder why you are spending more at the pump or changing those tyres more often. Nevertheless, a faulty hub will put unnecessary stress on your front transmission and you should take the vehicle in for a check as soon as possible so that you can determine if you need hub or transmission repairs.Share