Precision in practice
Aug 27, 2014 at 2:40 PM
During the daily grind, most people don’t stop to think about the wheel bearings on their cars.
The only time it comes to mind, really, is when a bearing goes bad and you have to pay to replace it.
At KBI, employees have bearings on the brain all day, every day. It’s their specialty.
In building an automobile, the vehicle’s axle is inserted into the wheel bearing, which carries the weight of the wheel, allowing it to spin without wearing the spindle or shaft. KBI’s technology reduces rotational friction in bearings on passenger cars and light trucks.
“It has to take the speed and weight of a car, which can weigh anywhere from 2,000 to 3,000 pounds,” said Howard Collins, a science teacher at St. Mary High School and a former New Departure-Delphi manufacturing supervisor. “And it has to be able to take cornering forces.”
Much precision goes into the production of a wheel bearing, which contains about two dozen steel balls. There’s forging and machining on lathes, with specifications within a millionth of an inch. That’s finer than a hair, and the accuracy can only be measured by special equipment.
Threads in the various components are within specific tolerances, as they have to link up with other car parts made elsewhere, Collins said.
The finish on wheel bearings must also be meticulously measured. If the finish is too rough, the balls can wear down and metal pieces will break off, causing pitting.
If something wasn’t within specification and the wheel bearing starts to fail once it’s on the car, the vehicle’s wheel will keep spinning, but it will wobble. The wheel could eventually seize up, and it would be impossible to steer the car.
Safe to say, a wheel bearing at KBI goes through about a dozen quality checks before it even makes it out of the plant.
All KBI employees undergo training, the duration of which depends on their job and the equipment they’ll be using. Some jobs, such as grinding, are a skill acquired after quite some time on the job. Slight atmospheric changes can require equally slight adjustments to the grinding equipment.
“It becomes an art,” said Sam Artino, a Huron city commissioner who retired from Delphi. “That skill level comes from time on the job.”
When those jobs disappear, the experience of skilled workers disappears along with them.
“The quality of products from overseas are not as good as ours,” Artino said.
Artino is one of several retirees who have joined active KBI (formerly Delphi-New Departure) workers in fighting for the factory’s future.
The plant has General Motors contracts in place until 2016, but after that, things are uncertain. The workers say foreign companies are underbidding on contracts in an effort to force American companies out of the market.