Do traveling salesmen still roam from farm to farm, selling magic in bottles, buckets and drums?
When I was young, our neighborhood could depend on several visits per year from various “mouse milk” salesmen who offered miracle lubricants and additives guaranteed to solve all our lubrication needs.
I always enjoyed the guys who had portable contraptions they’d hoist onto our shop’s workbench to demonstrate how much “slicker” their products were than whatever oil we already used. Kind of like the old Andy Granatelli TV ads for STP Oil Treatment, where Andy challenged people to grip between their index finger and thumb the tip of a big, heavy flat-blade screwdriver after it had been dipped in STP.
I was never able to prove or disprove the claims made by those traveling salesman. But in recent years I’ve had opportunity to talk with many lubrication industry experts, and can offer the following facts about modern oils and greases:
- The black slime at the bottom of gear oil bottles and buckets is the “good stuff.” Most additives to engine and hydraulic oil are liquid and stay in suspension, but some gear oils have Extreme Pressure additives like graphite or molybdenum that can settle during storage.
Agitating bottles or buckets of gear oil helps re-mix the additives, or you can simply include those dregs when filling a gearcase. Those additives may settle in the gearcase as a machine sits in storage, but the motion of the gears agitates and blends them back into the lube.
- Got a gearcase that’s running hot? Consider using synthetic gear lube. Larry Ludwig, chief chemist with Schaeffer Oil, says synthetic oils reduce gearcase operating temperature in two ways.
“Synthetic lubes reduce friction, and less friction means less heat,” he says. “Synthetic lubes also transfer heat more readily than mineral-based lubes. A gearcase is cooled when hot oil transfers heat to the wall of the gearcase, and then the metal radiates the heat to the atmosphere. Synthetics in-crease the transfer of heat from oil to metal.”
- Synthetic grease is generally more heat tolerant than mineral-based polyurea and lithium greases. It can tolerate temperatures up to 450°F. One combine manufacturer specifically recommends synthetic grease for their variable speed feederhouse drive sheaves to help deal with high operating temperatures. Consider replacing traditional grease with synthetic grease if heat thins polyurea or lithium greases to the point where they’re “runny”—or cooked.
- If a part doesn’t rotate a full 360 degrees, use molybdenum grease. Polyurea and lithium grease are excellent “universal” greases, but require full rotation to provide optimum lubrication. A component that oscillates without fully rotating, like spray boom hinges or cutterbar knife drives, are better served by moly grease.
