What Causes Bearing Failures?

Talk of ball bearings and the first thing a Porsche owner is likely to think of is ‘those tiny spherical things’ that make the car move. Yes, they are tiny but what they do cannot in any way be described as tiny. Without them, you won’t drive far. As a matter of fact, you won’t drive at all. That explains why you must always ensure your Porsche, as elegant as it is, always has perfectly worked and maintained Porsche ball bearings. This should be easy, given that ball bearings are relatively affordable. You will notice though that they sometimes fail no matter how cautions one is. This can happen due to a number of reasons such as.

Sudden Contraction

When a Porsche bearing is cooling off after use, the lubricant and the contracting metal air create a vacuum that is usually held by the seals. The seals sometimes fail to hold the vacuum so the sealed hub unit or the bearing sucks in water, debris and outside air. This always gets worse in places where salt is used on the roads as it expedites the wearing out process.  All these components find their way into the bearing. They then become deadly contaminants that circulate through grease, and in between the bearings and the races. The components then wear off and change their metallurgy.

Quality Matters

Porsche bearings are precision products. This means they always call for complex manufacturing processes. In simple words, inferior ball bearings that use low quality steel or use poor heat treating will always wear out and spall prematurely. Poor quality steel can also have the inclusion of soft or hard metal that can cause premature bearing failure. With that in mind, always remember that a cheap bearing may look and even feel the same as an expensive but high-quality bearing. What you cannot see is what makes the difference between a good bearing and a substandard one.

The quality of your preferred grease also matters. Think of it as your choice of engine oil. Value priced oil from a trusted brand will serve you better. In the same breadth, value priced grease for purposes of lubricating your bearing will keep premature failure at bay.


Avoid over tightening adjustable tapered roller bearings. It is an error that always results in premature failure. Tapered roller Porsche ball bearings at the front of Rear Wheel Drive Porsches are hardly ever preloaded. They are instead snugged up with at least 15 to 20 ft. lbs of torque power while rotating. This makes sure that the bearings are seated while the car moves. The adjustment nut on the other hand id loosed to 1/6 to 1/4 turn. It is then locked up in place with a new cotter pin. To make your work easy, ensure the endplay is always at 0.001 to 0.005 inches.

Sealing Issues

Seals play a significant role when it comes to longevity of your Porsche bearing. If contaminants from outside find their way inside seals, then they can easily cause a wear pattern referred to as bruising. That is why re-seals should never be used. Used seals always leak eventually. They then cause premature bearing failure or contaminated brake linings.