Wheel Hub: Testing and Inspection

FRONT

NOTE: The bearing contained in the Unit III front hub/ bearing assembly will produce noise and vibration when worn or damaged. The noise will generally change when the bearings are loaded. A road test of the vehicle is normally required to determine the location of a worn or damaged bearing.

Road Test
Find a smooth level road surface and bring the vehicle up to a constant speed. When vehicle is at a constant speed, swerve the vehicle back and forth from the left and to the right. This will load and unload the bearings and change the noise level. Where axle bearing damage is slight, the noise is usually not noticeable at speeds above 30 mph.

REAR
General Information
The rear hub and bearing assembly is designed for the life of the vehicle and should require no maintenance. The following procedure may be used for evaluation of bearing condition.

Inspection
With wheel and brake drum removed, rotate flanged outer ring of hub. Excessive roughness, lateral play or resistance to rotation may indicate dirt intrusion or bearing failure. If the rear wheel bearings exhibit these conditions during inspection, the hub and bearing assembly should be replaced. Damaged bearing seals and resulting excessive grease loss may also require bearing replacement. Moderate grease loss from bearing is considered normal and should not require replacement of the hub and bearing assembly.