VW stub axle. This is the short, bolt on, hardened steel axle that the center of the rear wheel bearings ride on. If the bearings fail, often times this stub axle will be damaged. Look for scratches or ridges, if they are present replace this stub axle or your new replacement bearings might fail as well. Sold each, driver and passenger side are the same.
To replace the VW stub axle on the Jetta, Golf, and New Beetle the rear brakes and hubs will need to be removed. The wheel bearing and hub is an integrated assembly and needs to be pulled off and pressed on the stub axle. To make sure you are doing the job correctly a Bentley Manual should be by your side. The Bentley manual has the proper torque specs for installing the stub axle.