Choosing the right bearing grease lubricant for your trailer has never been more complicated. The range of lubricants now available makes choosing the right one for your application like solving an ever-growing puzzle.
If you have been in the industry for a while, you might fondly look back at a time when one wheel bearing grease would cover everything that ever came into your workshop.
With the advance of vehicle technology, lubrication has become much more sophisticated. It might be more complicated, but in return we have much greater reliability and performance than ever. Trailers are no exception to this advance in technology, bringing with it an increase in choices but also greatly improved performance.
The first item that needs to be clarified is the NLGI number. This is a measure of grease consistency or relative hardness. (See table.) It does not refer to any other properties of the grease that would help you decide its suitability. For example, two greases could be identified as NLGI 2, one may be suitable for wheel ends and the other may be suitable for food manufacturing equipment. Just because it has the same NLGI number does not mean that it has the same properties or service life as the one you are replacing. Therefore, you can’t choose the correct grease simply from the NGLI number.
NLGI Consistency Table:
Wheel Bearing Grease
At one point, only one high temperature bearing grease was used for all wheel bearings, but this has been replaced by a variety of greases. The wheel bearing grease for standard Hendrickson wheel ends is heavy duty NLGI 2 lithium complex grease classified as GB or GC. While there are many lithium soap based greases, those with lithium complex thickeners have higher dropping points that allow them to be used at higher temperatures. Which is why it is important to look for lithium complex grease for wheel bearings. This type of wheel bearing grease is inexpensive and suitable for standard wheel bearings that are cleaned, inspected and repacked at regular annual intervals.
As wheel end systems become more sophisticated, a higher quality grease is required for premium long-life wheel bearings, such as Hendrickson HXL7, which are expected to go up to 5 years without rebuilding. These wheel ends need a grease that continues to lubricate throughout thousands of kilometres. The only grease available in Australia and approved for use by Hendrickson is Mobil’s semi-fluid Mobilith SHC 007. This is an NGLI 00 semi-fluid lithium complex grease that uses stable synthetic base oils. It provides thermal stability and oxidation resistance along with protection against wear, rust and corrosion. Additionally, it is compatible with other wheel end components, such as TIREMAAX PRO tyre pressure control systems. Therefore, this is an essential grease to have when working on Hendrickson HXL extended long life wheel ends.
Note: Never mix grease types. Bases, thickeners and additives of various greases will differ and may not be compatible. Always carefully clean out any old grease before applying any new grease.
Selecting the right grease can seem like a real puzzle and a waste of your time. Often the vehicle manufacturer might specify a lubricant rating or specification but the products you are looking at don’t list whether they meet those standards. Unfortunately, saying ‘This will do’ no longer meets the fine tolerance components of modern trucks and trailers now have. So, spending a little extra time up front to determine the best lubricant for the truck or trailer application can prevent unforeseen problems, reduce vehicle down time and greatly improve fleet productivity.