Wheel bearings are the link between the wheels and the trailer, making regular wheel bearing inspection vital. Thorough cleaning and inspection of the bearings during service is essential for trouble-free operation, especially those with long service intervals such as Hendrickson HXL wheel ends.
It is important to inspect the condition of wheel bearing grease before you begin cleaning to get an early indication of any potential problems. White or foamy grease indicates that it has been contaminated with water. Gritty or dirty grease indicates that it has been contaminated due to a failed seal. Metallic grey or small metal particles indicates that a component, such as a wheel bearing, has failed.
Wipe old grease out of hub and clean thoroughly.
Check the hub for serviceability. Clean and inspect the wheel bearing cups, wheel studs, wheel and hubcap mounting flanges and seal mounting area for damage, cracks, wear, fatigue or other damage.
Clean bearings in suitable solvent wash. Allow to dry thoroughly. Bearings must not be mixed up. Ensure they are refitted back to the same cup they came from.
Do not spin bearings with compressed air. Rollers could be forced out of the cage at speed causing possible injury and the bearing surfaces may be damaged by high-speed contact without lubricant. Bearings must be handled with great care to avoid any damage that could reduce service life. Do not reuse a bearing that has been dropped.
Thoroughly inspect the bearing rollers and inner race with a bright light, preferably with a magnifying glass.
Inspect bearing with bright light and magnifying glass.
Look for any wear, cracks, pitting discolouration or any other signs of damage. Replace any bearing that displays any of these faults.
NOTE: Always replace bearings as a set, inner and outer along with bearing cups.
If not immediately greasing the bearings after cleaning, give them a fine coating of spray lubricant to protect against corrosion. Remove any excess coating and wrap with a clean rag or place into a plastic bag. If you are storing the bearings for more than a day or so, then you should thoroughly pack with grease and rotate to coat internal surfaces, and store securely in plastic bags.
Bearing Cup Replacement Tip
Bearing cups can be difficult to replace, especially in aluminium hubs. The following steps will help you remove the hubs without damaging the hubs.
- Thoroughly clean the hub of all grease and oil. Failure to clean all flammable material from hub could cause a fire when welding.
- Using a suitable welder, weld a large bead around the centre of the bearing cup. Take care not to allow weld to blow a hole through the bearing cup, which would permanently damage the hub.
- Allow to cool for at least 15 minutes. This will allow the weld to shrink, which will cause the bearing cup to contract.
- Drive the bearing cup out of the hub from the other side of the hub with the punch.