Introduction: How to Diagnose a Faulty Wheel Bearing

By 4DIYers
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Video tutorial on how to troubleshoot a faulty wheel bearing. There are a few different types of wheel beings equipped on vehicles. First we have a tapered roller wheel bearing such as found on this Ford Ranger. These are designed to handle combined loads which includes radial and axial. There can also be a Conrad style wheel bearing, then an angular style wheel bearing which is able to handle more thrust. Styles wheel vary between vehicles, along with which is used on a drive, trailer, or steering wheels. For failed wheel bearing sound clips, I do have three examples which will be shown in this video. Maintenance intervals do vary between vehicles, some may need to be replaced at 250,000km or 150,000 miles, others may last the life of a vehicle. And even if one does require a replacement on your vehicle, that doesn’t mean the others are due for a replacement either. One side of the vehicle may fail 100,000km or 60,000 miles sooner than the other side.

Tools/Supplies Needed:

  • jack
  • axle stands
  • dial indicator
  • new replacement wheel bearing
  • ratchet and socket set

Step 1:

There are a few different types of wheel beings equipped on vehicles. First we have a tapered roller wheel bearing such as found on this Ford Ranger. These are designed to handle combined loads which includes radial and axial. There can also be a Conrad style wheel bearing, then an angular style wheel bearing which is able to handle more thrust. Styles wheel vary between vehicles, along with which is used on a drive, trailer, or steering wheels.

Step 2:

Maintenance intervals do vary between vehicles, some may need to be replaced at 250,000km or 150,000 miles, others may last the life of a vehicle. And even if one does require a replacement on your vehicle, that doesn’t mean the others are due for a replacement either. One side of the vehicle may fail 100,000km or 60,000 miles sooner than the other side.

The most common sign of a faulty wheel bearing is the excessive growling noise when driving the vehicle. The sound can be felt throughout the body of the vehicle, in the steering wheel, is incredibly loud, the tone will change at speeds, and the tone will also change when cornering. It will become notably louder when going into a corner at a higher speed too because you are putting more strain on the bearing, depending when way you are turning.

Step 3:

With a 1997 BMW 540i, I also had a failing front driver side wheel bearing. I caught this before it started making any noise when swapping over my winter tires. A failing wheel bearing any also be felt and heard when turning the hub by hand. I new bearing will be somewhat stiff when rotating which is from the grease inside. Eventually that grease will either dry out, wash out due to a failed seal, lose some of it’s lubricating qualities, or even become filled with worn material. So as the bearing gets older, it can turn more freely, eventually leading up until the point where the bearings overheat and expand or gather material and become galled. Galling is basically a flaw in the surface where worn material becomes imbedded on the surface from heat, pressure, and friction.

Step 4:

And finally you can use a dial indicator to check for hub runout. We are looking for any spikes or drops when the hub is rotated, this will show the hub is shifting over a galled or excessively worn surface. If wear is extreme, you may even be able to pull and push on the hub to show excessive play in the bearing too.

Step 5:

The sound normally starts out as a light clicking noise, as it becomes more worn, then you have a groaning or grinding noise.

This wheel bearing was from the drive wheel on a front wheel drive vehicle. As you can see it’s mounting to the spindle with a flange, then driving by the axle which fits into the spline of the hub and is held on with an outer nut or also known as a pinion nut.

As for the BMW, very similar system where the wheel bearing assembly is held by a flange on the spindle, but this isn’t a drive wheel, therefore there is no axle and no need for a spline.

Such as the wheel found on this 2wd Ford Ranger, as mentioned earlier it uses a tapered roller wheel bearing which is a serviceable design unlike the two examples from the BMW or Volvo. There is certain maintenance intervals where the bearing is disassembled, cleaned, new grease is applied and then torqued to spec.

I have saved the wheel bearing from the BMW, which I will be cutting down to give you a peak of what it looks like inside and hopefully I’ll be able to see the galling as well.

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