Ball bearings don’t seem to do much, but they do! Without them, your vehicle won’t run. The engine may roar to life, but that will only be for a short while. So how exactly do they fail? It is easy. When a ball bearing is cooling off after hours of use, the lubricant, contracting metal and air create a vacuum which is held by seals. If the seals fail to hold the vacuum, the sealed hub or the bearing unit will suck water, air and debris from outside. These contaminants circulate between races, bearings and through grease. In the process, the bearings and other components change their metallurgy. Before long, the bearings fail completely.
You will notice some looseness or wander in the steering. This may or may not be accompanied by noise from the wheel. You will however, notice some abnormal tread wear on your front tires. The noise may then become conspicuous each time you make a turn or accelerate. Be keen not to confuse this noise with pops and clicks produced by a worn out outer CV joint on a four-wheel drive car. A bad outer CV joint will always make noise when turning. It won’t make noise when driving straight ahead.
Consequences Of Ball Bearing Failure
Once your Porsche ball bearing is worn, the wear rate will be accelerated even further by seals that cannot keep contaminants out. There will also be increased heat. This will eventually expel lubricants off the bearing and lead to a sudden and catastrophic failure. In a nutshell, worn out bearings have everything to do with inadequate lubrication, improper adjustment and faulty installation.
Your mechanic will most likely want to find out why previous bearing failures occurred. The mechanic will also want to know what kind of roads you drive on and whether or not you load your vehicle to its maximum weight capacity. Note that Porsche ball bearing failure will always be inevitable if you overload your vehicle.
You will notice that bearings always fail from the passenger side of the vehicle first. That is because the bearings on the passenger side are exposed to more water standing in the gutter than the bearings on the driver’s side. This is not the case all the time though. If the bearings on the driver’s side fail first, examine the bearings on the passenger’s side. Failure won’t be too far.
Nearly all bearing components are usually heat treated so as to harden the metal. The heat treating process can only penetrate the metal to a certain level because the bearing is not heat treated to the core. Once the bearing has worn through the heat treated layer, failure occurs because the softer metal below is weak. This type of fatigue failure is referred to as ‘spalling’. It causes the metal to peel and come off in flakes. Keep in mind too that if a Porsche bearing overheats the hot lubricant will break down. This will result in an even etching of the bearing surfaces as well as scoring. The best you can do is to buy high quality bearings and while at it, buy high quality bearing lubricants.