| Symptom |
Investigate These Possible Causes |
| Rolling Contact Bearings |
| Noise |
Worn or brinelled bearing |
| High bearing temperature |
Overgreasing; insufficient application frequency; incorrect base oil viscosity; deficient EP performance of grease |
| Excessive leakage |
Damaged or incorrectly installed seals; overgreasing; excessive softness of grease; incompatibility of greases |
| Excessive bearing wear |
Deficient EP performance; insufficient application frequency; contaminating dirt or rust; bearing life exceeded; improper bearing installation; excessive grease stiffness |
| Plain Type Bearings |
| Overheating |
Improper distribution in bearing due to stiff grease or incorrect grooving; starvation due to insufficient application frequency or deficient mechanical stability of grease |
| Excessive bearing wear |
Starvation due to insufficient application frequency or defective/plugged lubricator; deficient load-carrying ability or temperature range of grease |
| Enclosed Gears |
| Excessive leakage |
Excessive softness of grease; incompatibility of greases |
| Noisy gear box |
Improper lubricant level or stiff grease |
| Overheating |
Improper lubricant level or stiff grease |
| Pitting |
Not usually grease-related, but heavier grease or base oil may retard progression of pitting |
| Wear and scoring |
If lubricant related, may be due to improper lubricant level incorrect consistency, EP performance or base viscosity of the lubricant or lubricant contamination |
| Open Gears |
| Gear wear |
Insufficient application frequency or incorrect lubrication |
| Build-up on gears or in roots |
Overgreasing; wrong type of lubricant; airborne dirt |
| Centralized Lubricants |
| No grease to points of application |
Depleted reservoir; pump malfunction; plugging; wrong type of lubricant; airbound system or damaged feeder lines |
| High system pressure |
Plugged metering devices; malfunctioning relief valve; excessive hardness of grease |
| Wet Applications |
| Noise/high wear |
Insufficient application frequency or incorrect grease; washout of lubricant due to overgreasing, improper grease consistency or incorrect thickener type |
| Excessive corrosion |
Wrong type of lubricant (inability to absorb water, inability to maintain structure or deficient rust inhibition performance) |
| High-Temperature Applications |
| Noise/high wear |
Insufficient application frequency or incorrect grease |
| Excessive leakage |
Improper thickener type, base oil viscosity or consistency of grease; incompatibility of greases |
| Grease hardening |
Deficient oxidation stability; improper thickener type; insufficient application frequency |
| Low-Temperature Applications |
| Restricted component motion |
Grease with insufficient low-torque performance or wrong base oil viscosity |
| Difficult application |
Grease with insufficient pumpability performance; wrong base oil viscosity or inconsistent quality |
| Freeze-up |
Deficient water absorption/shedding performance |