What Does I-X and U-X Markings On L44649 Bearings Mean?

Question:

Re-assembling two trailer hubs. Each hub has two L44649 R bearings, but I noticed one has an I-X designation and the other has a U-X designation. What is the difference please ? I presume its to designate inner and outer bearings, but cannot find any info to confirm and I dont know which goes where. many thanks.

asked by: Dave M

Expert Reply:

I cannot find any information on the I-X or U-X designation on your # L44649 bearings. This information is typically just a plant that made the bearing or the manufacturer.

It could mean inner or outer as you mentioned, but that would be assuming whoever installed them did it that way as the bearings themselves are the exact same.

When you're repacking the grease on hubs with a straight spindle like yours, and have them apart like this you need to keep track of which is the inner and which is the outer bearing as they really need to get back into the same race as the bearings and races wear in together.

Since you don't know which one goes where there's really nothing you can do at this point other than use your best guess of which went where, or replace the races/bearings with new ones # L44649 and # L44610, making sure to keep track of which is which for next time.

expert reply by: Samuel C