Servicing Pre-Adjusted Wheel Ends; Dos and Don’ts

Skill Level: Intermediate | Special Tools: None

To service pre-adjusted wheel ends and maximize performance, follow the DOs and DON’Ts below. Note: A spacer between the inner and outer bearings can identify a pre-adjusted wheel end.


• Clean the hub and all components during routine service intervals and when maintenance is required.
• Inspect the bearings, seal, spacer and hub for unusual wear.
• Replace the seal whenever the hub is removed from the spindle.
• Replace all bearings and the spacer if they show signs of wear. To maximize performance, replace them at the same time. Try the Timken Set-Right™ Commercial Vehicle Hub Rebuild Kits listed below.
• Use the same type of lubricant or compatible OEM approved lubricant.
• Follow your hub supplier or OEM’s service recommendations and procedures.
• Use the exact Timken® NP part number replacement bearings with pre-adjusted systems.


• Use the spacer if you are converting your pre-adjusted hub to a manually-adjustable wheel end system.
• Use industry standard components for pre-adjusted systems. Always use OEM specified service parts for replacements.
• Reuse components that are damaged or excessively worn.
• Mix oils and greases.


Following these simple Do’s and Don’ts will help avoid safety problems and limit the amount of unnecessary wheel end maintenance.
Dos and Don’ts
Note: Hubs with spacers require the use of exact NP part number replacement bearings to achieve the correct system setting range. Industry standard part numbers may be used only if the spacer is removed and the bearings are manually adjusted.

WARNING Failure to observe the following warnings could create a risk of death or serious injury.

Do not attempt to disassemble and reassemble unitized wheel end hubs and bearing assemblies. Improper reassembly could lead to failure.

Proper maintenance and handling practices are critical. Always follow installation instructions and maintain proper lubrication.

Tensile stresses can be very high in tightly fitted bearing components. Attempting to remove such components by cutting the cone (inner race) may result in a sudden shattering of the component causing fragments of metal to be forcefully expelled. Always use properly guarded presses or bearing pullers to remove bearings from shafts, and always use suitable personal protective equipment, including safety glasses.


CAUTION Failure to follow these cautions may result in property damage.
The products cataloged are application specific. Any use in applications other than those intended could lead to equipment failure or to reduced equipment life.

Use of improper bearing fits may cause damage to equipment.

Do not use damaged bearings. The use of a damaged bearing can result in equipment damage.


TechTips is not intended to substitute for the specific recommendations of your equipment suppliers. Every reasonable effort has been made to ensure the accuracy of the information contained in this writing, but no liability is accepted for errors, omissions or for any other reason.