This TIP is a general guide for checking bearing wear on the corrugator. Bearing clearance can be simply defined as the distance between a roll journal and its supporting bearing or the amount of “free play” in a bearing. In many cases however, the total movement measured may include eccentric clearances and wear and also sideframe or housing wear, in addition to the actual bearing clearance. This is often called “total movement” or “lift” in order to make the distinction. Determining the amount of movement in each of these components goes beyond the scope of this TIP and may involve removing end caps, bearing retainers, etc. To measure bearing clearances on a machine requires a dial indicator or gage and holder with magnetic base and a pry or lift bar. Bearing clearances are typically measured in 0.001 in. (0.0254 mm) increments. Note that the bearing clearances on heated rolls should be checked while the machine is hot!