ALT-1 What is the Typical Front Wheel Bearing Arrangement
Front wheel bearings have changed a little throughout the years since the invention of front wheel drive. With front wheel drive you have to deal with the drive axles riding on the bearings and that makes for a different design that is able to take more abuse. Rear wheel drive vehicles will use a stationary spindle that rides on the front wheel bearings. So let's look at what's typical for front wheel drive and rear wheel drive vehicles respectively.
Front wheel drive bearing arrangements have to allow for the drive axles to extend through them while giving them support within the spindle housing. Of course the bearing also provides the ability for the drive axle to spin freely. Typically these bearings are completely sealed for protection against dirt. To remove them you have to take them out as a unit. You may have to press them out of the housing or they may be bolted to it. Either way you will have to remove the break caliper (maybe even the caliper bracket), brake rotor and the drive axle to be able to access the wheel bearing.
Front wheel bearings are a little complicated to remove if you don't have the correct tools plus you will most likely have to undo the lower ball joint from the spindle to remove the drive shaft. Make sure you take the proper precautions if you decide to tackle this job. If the bearing will just unbolt from the housing then you have a much easier job, if it has to be pressed out then you will need the proper tools to insure you don't damage the new one going in.
For most rear wheel drive vehicles the typical front wheel bearing arrangement consists of two cone-shaped bearings and races housed inside of the rotor and packed with grease. The inner bearing and race are the bigger of the two. The races are pressed into each side of the rotor. The bearings run on the spindle which allows the rotor to spin freely and are sealed by a rubber grease seal on the inside of the rotor and dust cap on the outside. To repair or maintain these bearings you will need to once again remove the brake caliper and then the rotor. To remove the rotor you need to remove the dust cap, take out the cotter pin and remove the castle nut that keeps the bearings loaded. Once you remove the castle nut you will see a keyed washer and then the small wheel bearing that you can remove.
Then remove the rotor and on the backside you will see the grease seal. Remove the grease seal and you will find the inner (larger size) bearing. Once again the races are pressed into the rotor so they will stay with it. If you are just going to re-pack the bearings you won't need to remove the races. If you want to replace the bearings then you will need to drive out the old races.
With rear wheel drive vehicles that have pack-able bearings you will want to re-pack them about every 30,000 miles or at least when you have the brakes replaced. With front wheel drive sealed bearings you won't need to do any maintenance on these unless they start making noise and then you will have to replace them as a unit. Since they are sealed so well they rarely go bad, but occasionally they do.
If you think one of these sealed bearings is going bad and you are hearing noise from the front area of the vehicle, try driving down the road while you hear the noise then slightly turn the steering wheel left or right, (without driving off the road). If the noise goes away while turning then you probably have a bad wheel bearing, now you just have to determine if it's the right or left.
So there you have it, the typical wheel bearing arrangement for the front wheel drive and the rear wheel drive vehicle. As with any repair on a vehicle, having the proper tools will make things much easier, but even the proper tools won't make up for the lack of knowledge on how things are put together. I hope this helps compliment your knowledge on auto repairs.
