08 Nov How to Replace Wheel Bearings
Wheel bearings are vital in keeping your vehicle running safely.
These tiny components are what primarily bears the weight of a car’s mounted tyre/wheel assembly, reducing friction as the wheel rotates.
When do you know if you are experience problems with your car’s wheel bearings?
Bearings are surprisingly sturdy, lasting up to 160,000 km of driving or more, but over time they will wear out. When this starts to happen, a driver will typically hear scraping sounds while they’re driving and usually experience a slight “shimmy” because one or more tyre/wheel/hub assemblies will wobble during rotation.
While these signs usually signal bearing problems, brake and suspension issues sound and act in a similar fashion. When this happens, you should check out your car before you continue to drive with bearing issues.
Although replacing your wheel bearings is not all that difficult, however there are two different mechanical set ups existing in vehicles today. In the first case, an integrated approach was used in building the bearing structure, therefore the bearings cannot be lubricated, maintained, replaced or re-packaged on their own. This means that the vehicle’s entire bearing structure would need to be replaced since it’s all contained within a single unit, which makes the replacement process fairly easy.
Then again, some vehicles have been built using the traditional approach, which uses an outer bearing case. This usually holds for separate ball bearings and each of them can be lubricated, maintained and replaced individually. Because the latter approach is much more complicated, involving a lot more work, we will discuss the steps involved in this method as a baseline:
- Starting out, make sure that you park your car on a flat surface, and if it has an automatic transmission, put it in “park.” If the car has a manual transmission, put it in first gear with the parking brake set. This minimizes any movement when you lift the tyre/wheel assembly up off the ground.
- As an additional safety measure, place wheel chocks on all the tyre/wheel assemblies you are not working on to hopefully prevent your car from suddenly moving.
- Loosen the lug nuts on the tyre/wheel assembly you’re working on, while the car remains under suspension load. After this is done, you can jack the car up to allow you to work on the tyre/wheel assembly. Once this process is finished and the assembly is accessible, you can take the lug nuts off.
- Remove the tyre/wheel assembly and place it nearby.
- The brake calipers must now be removed (for a disc assembly) or in the latter case, the whole drum assembly.
- Take off the assembly’s integrated dust cover, the cotter pin and castle nut.
- Very carefully remove the drum or disc assembly.
- Unscrew each of the lug bolts and take the hub off the stub axle.
- You will find the bearing assembly all enclosed inside the hub, which means you need to open up the hub assembly to access the bearing assembly.
- Use a hub puller to open the hub’s “clamshell” to give you access to the enclosure where the bearings are.
- Once you gain access to the area housing the bearings, you can use a hammer, grinder or chisel to remove and replace the races and to clean up the knuckle.
- Using a degreaser, clean off the old grease and grime and any other ferrous material that needs to be removed and don’t be surprised if you run through a lot of shop rags.
- Once the hub backplane looks like it’s cleaned up properly, you can replace the races. Maintain the old bearings or you can replace the races with brand new bearings with the help of a bearing packer. Now that you’re finished, don’t forget to apply a liberal amount of grease on all the internal components.
- Put all your hub and brake assemblies back in reverse order.
- And lastly, replace the tyre/wheel assembly to finish the job.
The step-by-step process provided here is general information, just to show you how the process typically works, but every vehicle is different. To play it safe, do all your homework first as it relates to your car as well as your particular mechanical abilities, before you try this DIY project on your own.