Linear Bearings are designed to ride on smooth rods directly which can cause unwanted results if the bearings or the rods themselves are not suited to each other.
Consider upgrading your smooth rods also, if you feel that there is spalling (A small ground down track) on your rods where your bearings ride. This is a good indicator that the hardness on the rods are not ideal and it is recommended to have hardened rods installed.
When installing linear bearing on a horizontal aligned rod, it is best to follow the manufactures recommendation on the orientation of said bearings. This may be either with two ball "races" riding on the rod or one ball race. If you cannot find any manufacturer information, we recommend the bearings are seated with two races riding on top of the rods.
Please note that while most bearings are oiled during the manufacturing process this is typically used as a rust prevention is most cases and we highly recommend a application of aftermarket lubricant before using any linear bearing of these types. Maintaining your bearings with grease/oil periodically is also ideal to prevent undue wear or any performance issues (periods of approx. 6mths is ideal). The Rust prevention oil is harmless to other greases, though Misumi do recommend a application of degreasing before applying lubricants/grease.
We use Superlube PTFE oil or grease when required. But other common use lubricants can be just as effective, though these should not be used before conducting your own research as some lubricants may cause damaged or have little effectiveness.
As we endeavour to provide the best service we can to our customers, we encourage you to contact us if you have any other questions or concerns.