Making a gear change can swing the performance of a vehicle, and is sometimes required when you are making changes to other parts of a combination. Getting the gears setup in the rearend is only part of the battle, though — after that’s complete, you need to fill the pumpkin with the right gear oil. Selecting the right gear oil will prevent premature wear and parts failure.
There are various options available on the market for gear oil in terms of materials and weights. Different applications will have different requirements, and manufacturers have their own recommendations on what to use. US Gear creates gearsets for varying high-performance uses: from your basic street/strip car all the way to full-on race cars with big-time horsepower.
Cynthia Norris from US Gear explains what it recommends for its own products.
“Each application requires a certain type of gear oil based on the vehicle’s intended use. When it comes to gear oil, it’s important to consider different specifications, such as specific weight, grade, and oil brand. Using the right gear lube is crucial to maximize the life of the gear. It’s also important to regularly check the oil level and for any traces of contaminants or metal particles to ensure everything is running as it should. For standard differentials, we typically recommend EP 80W90 with GL-5 additive. Our partners, the axle manufacturers, have specific recommendations for different applications, as well.”
What keeps everything protected and rotating inside the rearend is the viscosity of the gear lubricant being used. You have to have a lubricant that is designed to deal with the amount of abuse you intend to put it through, otherwise it will begin to break down.
Barry Singleton from GearWorks works closely with US Gear, and explains more about what to look for in gear oil viscosity.
“Even a gear lubricant with a high viscosity needs to address the shock loads that are high enough to punch through the hydrodynamic film. When this fluid film is ruptured, the gears rely on the boundary lubricant additives for their survival. These are often corrosives like sulfur or phosphorus that, when squeezed hard, and heated, soften the surface of the gear and slide on that.”
Part of what goes into making sure the gear oil will function correctly is its chemical makeup and the kinds of Extreme Pressure (EP) additives that are being used. These EPs are used to assist in dealing with the shock loads that occur in high-performance applications like drag racing.
“There is an EP additive that is a favorite of ours: moly,” Singleton explains. “Molybdenum Disulfide in the form used for EP actually plates metal and then just slips, as a dry lube, when the oil film is penetrated. To me, the added expense of moly as an EP is a no-brainer. It should be obvious that you can’t rely on the EP too often, as it will become depleted and it’s hard on the gears. The real trick in all of this is to have an oil that is of sufficient viscosity to keep a fluid film in place the majority of the time.”
If you have questions about getting the best gear oil for your US Gear products, make sure you head to their website here to ask their knowledgeable staff any questions you might have. You can also learn more by clicking here and checking out the GearWorks website.