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eBay£27.95Visit shop Red Line 75W90 NS GL 5 Non Slip Diff Gear Oil. Diff Gear Oil. 1 US Quart (946ml)
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The Red Line 75W90 NS GL-5 is a fully synthetic gear oil designed for manual transmissions, transaxles, and differentials, particularly favored in competition settings. Its key benefit is providing the highest level of component protection under extreme conditions for improved performance and longevity, while also lowering operating temperatures and facilitating easier gear shifting across a wide temperature range. A key caveat is that it is not recommended for standard road car use due to the absence of friction modifiers, which can lead to clutch plate noise; however, Red Line friction modifier can be added for quieter operation if needed.
| Model Part Number | 58309 |
|---|---|
| Brand | Red Line |
This oil is specifically formulated for high-performance and competition use. While it offers excellent protection, its lack of friction modifiers can cause noise or chatter in standard road car transmissions, particularly those with clutch-type LSDs. For typical road use, a GL-5 oil with friction modifiers might be more appropriate unless you intend to add Red Line friction modifier.
It is generally recommended to avoid mixing different types of gear oils, especially synthetic and mineral-based oils. For best performance and to maintain the properties of the Red Line 75W90 NS, it's best to use it as a complete fill without mixing.
Consult your vehicle's owner's manual or the manufacturer's specifications. Most manual transmissions and differentials from the 1970s onwards requiring a gear oil specification will typically call for GL-4 or GL-5. GL-5 is generally suitable for both manual transmissions and differentials, whereas GL-4 is often recommended only for manual transmissions.
The 'NS' in Red Line 75W90 NS stands for 'Non-Slip', indicating that it does not contain friction modifiers. This is beneficial for clutch-type Limited Slip Differentials (LSDs) as it allows them to lock up fully without interference from friction-reducing additives.
The amount of friction modifier to add depends on the specific application and desired noise reduction. Consult the Red Line Oil technical data sheets or contact their customer support for precise recommendations based on your vehicle and LSD type.
Gear Lubricant (GL) ratings, defined by ASTM D5182, indicate the extreme pressure (EP) performance of gear oils. GL-5 oils offer a higher level of EP protection than GL-4, making them suitable for hypoid gears in differentials that operate under severe conditions. GL-4 oils provide less EP protection and are often recommended for manual transmissions where GL-5 might be too aggressive for certain yellow metals (like brass or bronze synchronizers).
Verify the correct oil viscosity and specification (GL-5) for your transmission. Ensure the oil level is correct. If the issue persists, the transmission may require mechanical attention.
This is expected in some road applications due to the lack of friction modifiers. Add Red Line friction modifier as per their recommendations to quiet the operation. If using in a dedicated competition vehicle with an LSD, this level of lock-up is often desired.
Check all seals and gaskets for wear or damage. While synthetic oils can sometimes highlight existing seal weaknesses, ensure all connections are properly tightened and seals are in good condition.
Compatibility: This oil is GL-5 rated and designed for manual transmissions, transaxles, and differentials. It is particularly suitable for clutch-type Limited Slip Differentials (LSDs). It is *not* recommended for road car use without modification due to the lack of friction modifiers, which can cause noise or chatter with certain clutch packs. If quieter operation is desired for road applications, Red Line friction modifier can be added.
Setup: Ensure your vehicle's manual specifies a GL-5 gear oil. Consult your vehicle's service manual or a qualified mechanic for the correct oil capacity. Always use clean equipment when filling to prevent contamination.
Care: Store the oil in a cool, dry place away from direct sunlight. Ensure the container is tightly sealed when not in use. Follow the manufacturer's recommended service intervals for changing gear oil, or consult with performance driving specialists for more aggressive usage recommendations.
