Timken use to offer a lot of thier Timken tapered roller wheel bearings in many different quality of bearings with the same part number except the suffix. I complained once about the price of a set of wheel bearings on my small single engine airplane when I had the fisrt annual inspection done on it, the shop charged me around $38.00 for the bearing and race, the same part number at the local auto parts store was $8.00 The auto parts bearing had a A suffix and the airplane bearing had a G suffix on it The FBO shop mechanix explianed the difference was in how close the tolerances where between the two, .0010 compared to .0001
That airplane took off and landed at 85 MPH + and the tires where very small in diameter so the wheel bearings on landing would go from a dead stop to real fast in a very short period of time I put a bunch of time in that airplane, 1100+ hours and a lot of take offs and landings in that time and never had another wheel bearing failure after the first annual, I did remove and repack them every 100 hours per the factory recommended servicing That airplane had sat in northern CA for in a hangar 18 months on the north end of San Fransisco bay area for 18 months before I bought it so the salty air moisture content up there may have cause the pitting on the bearings and races I now buy the recommended bearings from the manufacture for that specific application