Servicing Aircraft Wheel Bearings
Light aircraft wheel bearings need to be serviced too every now and then. Some aircraft manufacturers recommend it every year where as other manufacturers recommend 200 or more hours (even with the same type and brand of bearings).
The job is not a very difficult one, somewhat greasy maybe. It can be done in about one hour per wheel/bearing and if done properly it will keep the aircraft rolling smoothly for many years to come.
We also have a document on this page were we explain the procedure in great detail and show it clearly on images. This document can be downloaded and printed for reference on the job.
So, study this page and the howto document and be prepared to get your hands dirty. The result is smooth rolling aircraft, with proper tire inflation of course.
Aircraft Wheel Bearings
Wheel bearings take the load of the aircraft during landing / rolling and especially in crosswind situations. The loads on the construction are enormous compared to the total rolling surface of the bearing cone which is small. Proper maintenance is therefore imperative for long service life of this bearing.
It is important to have the wheel bearings serviced to standards for minimum rolling resistance during takeoff and landing. If not greased properly the bearings can overheat to the point where a fire hazard is possible, creating a whole new problem altogether.
Describing how a wheel bearing is constructed would take pages, so we start off with this picture of a complete main wheel assembly which shows everything in detail.
Our maintenance concentrates from the wheel half and the wheel bearing itself (shown above as bearing cone) and all parts up to and including the retainer ring. The tire itself will be discussed in our next article.
Service Document "How-To"
As already said: all parts from bearing cone to the retainer rings on either side of the assembly shown above are the subject of our included pdf document. This describes how to take the bearing apart and maintain and grease it to aviation compliant standards.
The next link takes you to a Dutch / English document describing how to service an aircraft wheel bearing in great detail. This 27 page document is full of detailed pictures and is rather large, so downloading will take some time.
This how-to was written by Jordi van Eden, A&P Mechanic, van Eden AirCraft Technics. Feel free to distribute but leave the copyright in place.