Taper Roller Bearing Lubrication - Oil or Grease?

[Rangemaster1]

Years ago a good friend, who is quite knowledgable in the use of lubricants, told me to never use moly oil or grease in roller bearing because it would act as an abrasive. He said it would be like putting very fine sand in the bearing. I've heard similar arguments from other sources. On a sliding surface, it's a wonderful lubricant since it has an affinity for metal and wants to adhere under extreme conditions.

Some moly greases are designed for use in roller bearings, but there is a specific formula. If you are unsure of the grease you intend to use, either research it to be sure, or use another high quality product to be on the safe side.

Good luck,
Ron

 

[Cadillac STS]

Years ago a good friend, who is quite knowledgable in the use of lubricants, told me to never use moly oil or grease in roller bearing because it would act as an abrasive. He said it would be like putting very fine sand in the bearing. I've heard similar arguments from other sources. On a sliding surface, it's a wonderful lubricant since it has an affinity for metal and wants to adhere under extreme conditions.

Some moly greases are designed for use in roller bearings, but there is a specific formula. If you are unsure of the grease you intend to use, either research it to be sure, or use another high quality product to be on the safe side.

Good luck,
Ron

I would agree that the type of grease used can be important. But grease most definitely can be used. Every car and truck in the world uses taper roller bearings in the wheels with grease, more often than not daily highway use. And the bearings hold up just fine with never adding more grease.

 

[GrahamT]

Seems like the grease vers. oil for bearing lubrication is still up in the air. Correct bearing selection, fitting and, most important, contamination control are probably the most important factors to consider in deciding overall bearing / machine performance. If you are a hobby machinist who likes to run and maintain a lathe to as high a standard as he/she can reasonably achieve, then oiling the headstock bearings every time before you run and, during, is second nature. With my old Drummond, taper cone bronze bearings there is no choice, oil cups and cone adjustments on a regular basis. On my new import with taper rollers it will be grease, contrary to the manual which states oiling with their `special lubricant` available in 5 gallon pail!
Ironic that when I followed the running in procedure, lubrication, times and speeds, the noises and black gritty goo coming out of the spindle bearings prompted me to stop and pull the warming spindle out to check what was going on. Race surfaces scuffed, oil loaded with contamination and metal particles, just what you need ina new machine!
Finally, back to lubricants. Oil lubrication; Rolling surfaces, oil bath/splash or continuous oiling is essential with more chances of introducing contamination into the bearings.
Grease lubrication, meticulously done once, on inital assembly, with an application suitable CLEAN grease and handling will maintain extended machine performance without the risk of introducing contaminants. In fact, a test study done years ago by Rolls Royce PLC, showed that rolling element bearings properly installed and running within their specifications and with ultra pure lubrication would perform indefinitely.
Other alternatives are pre lubricated sealed assemblies or bearings with lubricant loaded polymer inserts.
Graham

 

[Kernbigo]

i used rebuild high speed grinding spindles and bearing manufactures will tell you oil will out last grease 6-8 to one over grease, but you have to either oil mist or conatus oil running on the bearings

 

[Ulma Doctor]

I would agree that the type of grease used can be important. But grease most definitely can be used. Every car and truck in the world uses taper roller bearings in the wheels with grease, more often than not daily highway use. And the bearings hold up just fine with never adding more grease.

Just a point of information-

A lot (most I ever worked on) of the over the road trucks use 90wt oil bath tapered roller bearings on the drive and steering axles

grease would be suitable for sealed bearing use in a lathe headstock provided that the correct amount and type of grease is chosen
Too much grease can be as detrimental as not enough