PG.349-456 10 Troubleshooting Scenarios [oils and lubricants]

A technician performs drop lubrication on a mechanism with short, periodical work cycles, but applies the oil while the machine is still running. The operator later reports unusual noise and wear. What is the mistake?

Applying drop lubrication while the equipment is running.

Correct action: Drop lubrication must only be done when the mechanism is at a complete standstill and the drive motor is locked out (per company safety regulations). Doing it while running violates safety rules and risks uneven oil distribution or injury.

A conveyor chain system with continuous long cycles is being lubricated using a manual brush instead of an automatic drop dispenser. The chain is wearing out faster than expected. What is the mistake?

Using brush lubrication on a continuous/long-cycle system.

Brush lubrication is only for low-speed equipment requiring heavy oil that must stick to gear teeth or chain links. For conveyor chains with continuous or long cycles (minimum to average power), the manual explicitly recommends a drop system through an oil dispenser (oiler reservoir + oil flow valve). A manual brush cannot provide consistent oil flow while the chain runs, causing periods of dry friction and accelerated wear.

An oil-bath lubricated gearbox is refilled with fresh oil without first removing the impurities that have settled at the bottom of the housing. The bearings begin failing prematurely. What is the mistake?

Not removing settled impurities before adding fresh oil.

The manual warns that oil-bath (splash) systems require “more frequent oil changes. At the same time, impurities that have settled at the bottom of the housing must be removed to prevent contamination of the fresh oil.”

A large speed reducer (heavy equipment) is being lubricated with occasional manual spray from an aerosol can instead of a circulating system. Gears and bearings overheat and score. What is the mistake?

Using spray lubrication on heavy equipment instead of forced oil.

Spray is for small mechanical equipment and is applied when the equipment is at rest. For large speed reducers, the manual requires forced oil (automatic spraying device that also serves as the reservoir, with pumped and vaporized oil reaching all contact points).

A forced-oil system on a gearbox shows cloudy oil and corrosion. The reservoir has a standard breather but no desiccant dryer. What is the mistake?

Using a standard breather instead of a desiccant dryer.

The manual states: “Desiccant breathers help remove atmospheric moisture as the oil level changes.” Without it, humidity enters during temperature-induced expansion/contraction, causing moisture contamination and cloudy/corrosive oil.

Technicians never check the sight glass on an oil-bath bearing housing. The oil level is now well below the center of the lowest ball. The bearing is running hot. What is the mistake?

Failing to monitor the oil level with the sight glass / bull’s-eye gauge.

The manual shows the critical oil level must reach the center of the lowest ball (oil bath level). Running below this causes inadequate lubrication and overheating.

A multi-point distribution system using a sight-feed lubricator has the oil flow valve installed upside-down (mark not at top). Some lubrication points receive almost no oil. What is the mistake?

Incorrect orientation of the oil flow valve (“Mark in top” must be at the top).

The manual diagram explicitly labels “Mark in top” and “Oil flow valve” on the 84 mm spaced system. Installing it upside-down prevents proper gravity feed and calibrated drop delivery

Gearbox oil has become very dirty, but no external portable filter has ever been used. Wear particles are circulating and damaging components. What is the mistake?

Not using external portable filters (Kidney Karts).

The manual states: “External, portable filters are often used for cleaning gear box oil. These are commonly called Kidney Karts.” Forced-oil systems rely on them to remove contaminants when internal filters are insufficient.

A low-speed chain drive is being lubricated with a very light oil that flings off immediately instead of a heavy oil applied by brush. The chain is stretching and wearing rapidly. What is the mistake?

Using the wrong oil viscosity for brush lubrication.

Brush lubrication “applies to low-speed equipment requiring heavy oil which will stick to gear teeth or chain links.” Light oil does not adhere and is flung off, leaving the chain dry.

A bearing that operates under heavy load and infrequent lubrication is packed with a grease that has very low adhesion (no soap thickener). The grease leaks out quickly, allowing water ingress and corrosion. What is the mistake?

Using grease without soap thickener.

The manual explains: “The lubrication process is also made easier when soap has been added to the oil, thanks to the excellent adhesion characteristics… which cuts leaks down and enhances water tightness and prevents contamination. Moreover, soap increases the load-bearing capacity.” Without soap, the grease cannot stay in place or seal properly.