Bearings are made of high-grade steel that have a super hard coating over the rollers, inner and outer races. A bearing goes bad when this coating wears away due to mileage or extreme load and leaves just the normal steel which then degrades and destroys the bearing components. Also, failures can occur when moisture combined with salt from roads penetrate the seal and contaminate the bearing, or over time the grease used to lubricate the bearing can liquefy leaving it dry causing a failure. Replacing seal bearings off trucks is a critical job and must be done using the right equipment, BrakeMate® Limited is your go to stop for the perfect maintenance equipment.
A Failed Seal
The main killer of solid axle wheel bearings is a failed seal. Most seals ride on the axle shaft, and they typically have a lip and a spring that holds the lip to the axle. When a seal is installed, it takes time to install the axle. Splines can damage the seal and cause leaks. The area on the axle shaft where the seal and bearings make contact must not be rusted. Use fine-grade emery paper to clean the axle shaft between the flange and the worn area. If the surface is grooved or damaged, the axle can be repaired with a sleeve on some applications. If not, replacing seal bearings on trucks is the only option.
To Do’s Before Replacement
Before replacing seal bearings off trucks one must make sure the seal is installed correctly. A correctly installed bearing may extend out from the housing up to 1/4”. Some axles have small seals that must be positioned properly so pressures can be relieved and the lip can work. Ensure the breathers on the axle are not clogged. If clogged, the heating (increased pressure) and cooling (negative pressure) of axle will cause pressure fluctuations that will cause the lips of the seals to deform and leak. Any leak on an axle should be taken seriously. Ignoring a leak can be very expensive and destroy the bearings, brakes and differential.