Winter weather/handling & storing lubricants
- What is the key to engine protection, as it relates to lubricants, for winter weather?
- How does the cold affect your engine?
- How should owner/operators or fleets change their practices when it comes to protecting transmissions and differentials during the winter months?
- How does truck engine idling impact fuel economy and vehicle operation?
- How can winter impact suspension systems and lubricant requirements?
- What problems can the incorrect winter weather lubrication cause in a heavy-duty truck? What are the solutions?
1. What is the key to engine protection, as it relates to lubricants, for winter weather?
During the winter, all vehicle lubricants — whether engine oil, transmission oil, differential oil, hydraulic oil, or grease — should be considered.
Before starting equipment in extremely cold temperatures, an operator should make sure the oils in the engine, transmission, and hydraulic system are fluid enough to flow. Check the oils by removing the dipstick. If the oils drip from the dipstick, then the lubricants are fluid enough to pump.>>back to top
2. How does the cold affect your engine?
While most 15W-40 viscosity grades will satisfy the cold start-up temperature requirements in the United States, engine oil specifications should be referenced to ensure that properties such as pour point, cold cranking viscosity, and cold-temperature pumping viscosity meet an engine's coldest operating temperature requirements.
Premium engine oils such as Mobil Delvac 1300 Super 15W-40 are formulated to provide increased cold weather start-up protection at temperatures as low as minus 15°F. Also, another option that fleets or owner/operators will want to consider is using a semi synthetic like our Mobil Delvac Elite, or our flagship Mobil Delvac 1 ESP, which is a fully synthetic motor oil formulated to deliver exceptional protection under the most demanding cold weather conditions.
Engines will experience the highest wear during cold start-up, as lubrication to bearings and the upper-engine hardware is limited during start-up and initial warm-up. The engine oil's viscosity at starting temperature is an important factor in determining whether or not an engine will start.
Using too heavy a viscosity during cold temperatures can result in inadequate lubrication during start-up.
If the chosen lubricant has a viscosity that is too high, the oil filter bypass valve opens and will allow unfiltered oil to bypass the oil filter (the bypass valve maintains lubricating oil flow to the engine and prevents an oil filter collapse). The bypass valve will close as the engine oil warms up and thins out. It is equally important to adequately warm up an engine before loading it. The best practice is to idle for a short period and warm up the engine by operating at a low rpm and load condition. >>back to top
3. How should owner/operators or fleets change their practices when it comes to protecting transmissions and differentials during the winter months?
As temperatures drop, the same cold-temperature viscosity phenomenon occurs with drivetrain lubricants as it does with engine oils. Following the engine warm-up procedures mentioned above will also allow for sufficient oil circulation to your drivetrain components.
For general-service transmissions used in on-highway Class 8 vehicles where ambient temperatures of -15°F or below exist, a heat exchanger is recommended to make warm-up times faster.
Fully synthetic SAE 50 transmission and SAE 75W-90 gear oil lubricants, such as Mobil Delvac Synthetic Transmission Fluid 50, will provide better low-temperature fluidity than conventional oils, as well as help reduce wear, leading to longer equipment life and allowing for easier gear shifting while operating cold. >>back to top
4. How does truck engine idling impact fuel economy and vehicle operation?
Many truck engines idle for very prolonged periods during cold winter temperature conditions to allow for warm-up and to keep the cab warm. Prolonged idling will reduce engine life and also waste fuel. Engines operate cooler while idling and during long idle periods in winter's cold temperatures, moisture in the intake air can condense in the engine crankcase and produce corrosive sulfuric acid which can attack soft bearing alloys. Long idling also contributes to increased soot, and combustion contaminants which will shorten the engine oil's life prematurely, and can lead to excessive piston deposits, sludge formation and detrimental viscosity effects. >>back to top
5. How can winter impact suspension systems and lubricant requirements?
During winter weather conditions, vehicle suspension components can be subjected to more adverse conditions such as increased water and contamination from road salting. Careful attention is needed to ensure that the suspension components are greased at a regular interval and the proper amount of grease is applied to help minimize the entry of road contaminants and to replace grease that has been washed out due to excessive water exposure. It is also important not to over grease components as this can rupture seals and lead to reduced component life. A ruptured seal can lead to loss of grease and lack of lubrication as well as intrusion of road contaminants, water dirt, etc.
Differentials and wheel hubs can be exposed to increased water intrusion during winter months from wet road conditions, high water at curbs, road flooding, etc. The lubricant condition should be inspected for water contamination when levels are checked. A visual inspection that shows a hazy or cloudy appearance or visible water droplets can indicate an excessively wet lubricant. Any indication of water intrusion should be investigated for the cause and the lubricant changed. >>back to top
6. What problems can the incorrect winter weather lubrication cause in a heavy-duty truck? What are the solutions?
Overgreasing the fifth wheel latch mechanism will tend to cause the latching mechanism to operate improperly (latching correctly). This can prevent the latch from locking properly on the trailer king pin and could result in an accident by dropping the trailer. Overgreasing also makes the fifth wheel latch difficult to operate during cold temperatures, which drivers often complain about.
A truck's greased components are subjected to more adverse conditions during winter weather conditions. Adequate grease is critical to ensure long component life and to keep out contaminants. Since grease is harder to pump and flow under cold-temperature conditions, it is important that truck shops ensure their grease equipment is maintained and adjusted properly to ensure good pumping pressure and grease flow through the entire grease dispensing system to the grease gun nozzle. Any leaking lines, hoses, grease guns, should be repaired or replaced. Air pressure to the grease pump must be adjusted to ensure the grease pump pressure and volume will ensure good grease flow and pressure to the vehicle greased components. Technicians should also visually ensure clean grease is purged through all outlets of the components, e.g., all trunnions on a U-Joint.
Truck or trailer units utilizing on-board automatic grease dispenser systems should ensure the proper grease product is being used to ensure good flow under cold temperature conditions and the lubricator is adjusted to provide adequate pumping under cold-temperature conditions as the grease will be harder to pump as temperatures decrease. Inadequate flow will lead to early component failure. If the current grease product is not performing under cold temperature exposure, consider dropping to a lower NLGI grade and consult your lubricant supplier. >>back to top
