Keep the show on the road as Borgy gives us a crash course on the ins and outs of a camper trailer’s wheel bearings

If you’ve ever had a wheel bearing seize half-way through a camping trip, you’ll agree it’s a massive inconvenience! As luck would have it, they’re the most common component to fail out on the tracks, which poses a problem. You see, not only do they help support the entire weight of your vehicle/ trailer, but they also play an absolutely crucial role in keeping your set-up rolling. Yep, to put things simply, if a wheel bearing goes bang, you go nowhere!

So, it kind of makes a little sense to get a better understanding of how these little buggers actually work. So, breakout the fine wine and hold onto your hats; the next few pages could seriously save you some precious time and money in the long run.

How They Work 

Ask a mechanic what’s wrong with your trailer and the technical explanation you’re likely to receive is “your wheel is buggered mate!” But the real question is, what actually happens? Better yet, how do you ensure it doesn’t happen again? Well, let’s start by saying the less friction there is, the easier it is for an object to move. Afterall, it’s easier to roll a tyre than to slide or drag it along the road, right? When it comes to the tyres on our 4WD and camper, we need them to spin independently to the rest of the set-up, without much friction at all. A wheel bearing’s main purpose is to reduce friction and allow opposing objects to roll or rotate without damage. They do this by using smooth metal rollers or balls to “the load”, which sit between a smooth inner and outer metal race/ surface with some sort of lubricating grease or oil thrown in the mix.

What Goes Wrong? 

Most, if not all wheel bearing failures can be put down to an increased amount of friction, which causes a build-up of heat capable of melting, distorting, cracking and fatiguing the metal components – not fun at all! This excess friction is usually caused by a lack of lubrication; things like an insufficient amount of grease, or even unsuitable or contaminated grease which has lost its lubricating properties, are the main culprits. Too much load placed on the bearings will do it too – it’s a bit like strapping an object down to the back of the ute; the tighter you pull down the harder it is to move.

Most buggered bearings you’ll find physical damage like etching, scuffs, chips and scouring on the rollers and races, but when they really go bang, we’ve seen them melt to the stub axle, seize up and literally snap the stub axle clean off!

Early Warning Signs

Caked up clumps of grease, discolouration or any signs of moisture are good indicators that excessive heat won’t be too far behind. If a hub assembly gets too hot to touch comfortably, it’s a good indication there’s a problem. Grease spraying out onto the rim is another indicator that heat and pressure has built up, too.

It’s also worth jacking the wheels up before a trip away and checking for free play by wriggling the wheel from top to bottom. Also, if you loosen the brakes up a bit and spin the wheel it should rotate nice and smoothly with minimal drag. Grinding or whirling noises definitely warrant further investigation, although sometimes the brake assembly can be the cause of this one.

Safe Not Sorry 

If the hub assembly has been getting hot, it’s worth replacing the bearings as the metal integrity may have already been compromised. Also, have a good hard look at the stub axle for hair line fractures or cracks, especially on the underside and around any steps in the metal; catching this early could save you a big nasty headache!

Roadside Routines 

Make it part of your routine to check the wheel bearings every time you stop for fuel. You don’t have to pull them apart, just have a quick look for any visual signs like grease spray on the rim or too much heat. It’s also good to do a basic check for free-play by grabbing the top of the tyre and pulling it back sharply towards you with a fair bit of oomph – you’ll know when it’s loose!