What is the truth about "wheel separation"?

I can't say that I've ever had one myself after 20 plus years of driving. I have had a cap break loose, felt it, caught it before it flew off and got off the road quick enough to avert any incidents but never lost a wheel (knock on wood).

I take my pre-trip seriously and have been labeled accordingly for putting things out of service if I feel they are a problem.

Fortunately, with the company I'm with, they are great communicators, take good care of the equipment and are conscientious about safety concerns (and I didn't say that because they might be reading this stuff... they actually are one of the better companies I have ever worked with).

 

What is interesthing about the youtube video's is the fact that they were all cases off not wheels coming off the hub but the complete hub with wheels coming off,which mean they were bearings that broke which is much harder to detect as a driver

 

It's a mechanical device.

It's not if, just WHEN it will fail.

You can learn the signs and symptoms of those indicators and then change it before hand.

But you aren't going to stop it.

 

My background is industrial management, mechanic and manufacturing engineering.

As "manufacturing" has progressed over the years, it's actually become it's own worst enemy. Management wants things done cheaper for for less cost.

Engineering obliges them by taking out material from the product reducing cost at the expense of service life. Not saying that things made 50 years ago were ALL better, but the things that mattered at times were.

Materials have been changed and removed from the product to the point where the service life of a component is KNOWN when it will fail. It's often NOT published much from manufacturers because they are telling you then when to expect to have to replace something. It would open up a legal nightmare for them as well at that point.

Example.

Turbo's have a service life of around 600,000 miles. They are often warrantied for 400-500K miles. Why? because they know when the service life will be up and someone will get rid of the main end item (the truck) before the components start to fail. Components being; starters, a/c compressors, air compressors, fuel pumps, injectors etc.

Tires, rims and suspension components are similar mechanical devices that will have known service lives as well.
They have fatigue cycles that are well documents and have specific test protocols to determine them.
http://standards.sae.org/j1095_200910/

And you wonder why things cost what they do.

Before that product even GOES to market, an engineer can tell you when to plan on replacing it. And you think they want the consumer to know that? Every competitor on the market will use that information against you to put you out of business.

 

I've been a mechanic for 20 years and I have seen it more than a couple times. Not on trucks, but trailers. Both wheel separation from fastener failure and bearing failure. (losing one wheel,or the set from the axle) Fastener failure is much more common. And I'm sorry to say lack of proper maintanence is the most common issue. I am just learning of the importance of replacing old, rusty rims, and fasteners on a regular basis. Proper torque is vital to insure clamping of the rims to studs or hubs. Not only do those old rims look crappy they are dangerous to the safe operation of the vehicle. A good thorough pre-trip will help find issues before they become serious. Look for those rust trails from lugs and nuts and reach down and grab those lugs. You might be surprised what you find loose.