Editor's note: The following article is a response by Timken Co. to questions on formed hubs. More technical resources on the company's automotive products are available at Timken's website.
CANTON, Ohio — At Timken Co., our automotive product specialists have been receiving many questions regarding the use of formed hubs on both driven and non-driven versions of the same application.
Traditionally, manufacturers have relied on the bearing companies to design separate hub unit bearings for the non-driven and driven versions of the same application.
The driven version of the hub unit bearing would have a spline cut in the inside diameter to accept the drive-axle shaft, and the non-driven version would use either a solid hub or dead spindle design. The dead spindle design requires the use of additional components such as nuts, spacers and washers.
Our Formed Hub technology allows the same hub unit bearing to be used on driven and non-driven wheels, replacing the solid hub or conventional nondriven dead spindle design.
Some automobile manufacturers have started using the same Formed Hub on the front and rear of the vehicle.
We often see installers question why the hub unit bearing on a non-driven wheel has a spline cut in the inside diameter to accept the drive axle shaft. We explain to the installer that these part numbers came from the factory this way and others were converted to a Formed Hub in the aftermarket.
Designs converted for the aftermarket have been tested and validated per the OEM specifications for both driven and non-driven wheel ends.
The Formed Hub part numbers are installed the exact same way as the solid hub or non-driven dead spindle design they are replacing.
Even though the spline is not necessary for a non-driven application, it allows us the chance to commonize components for simplicity and cost savings.
From a performance standpoint, the Formed Hub will improve performance by holding the bearing setting more consistently (see above illustration).
Unlike a traditional thread and nut design on a non-driven wheel, there is no chance for the nut to loosen and back off. The resulting system stiffness reduces rotor runout and increases brake system life. And as a self-contained, tamper-proof module, the Formed Hub is designed to be good for the life of the vehicle.