Cusco LSD Oil – 80W-90 | API GL-5 | Mineral | 1 Litre | 010 001 L01

Cusco 010 001 L01 LSD differential oil, 80W-90 viscosity, API GL-5 rated, mineral (non-synthetic) base, 1 litre. Formulated specifically for Cusco clutch-type and plate-type limited slip differentials in rear-wheel-drive and four-wheel-drive rear differential applications. Also compatible with open differentials requiring GL-5 80W-90 specification fluid. 1.5 lbs. Ships fast across Canada and the US.

Why LSD-Specific Fluid Matters

Mechanical limited slip differentials — including Cusco’s 1-way, 1.5-way, and 2-way clutch-type and plate-type units — rely on friction between clutch discs and pressure plates to control torque distribution between the driven wheels. The friction characteristics of the differential fluid directly determine how the LSD engages, how progressively it locks, and how long the clutch pack lasts:

• Standard GL-5 gear oil with friction modifiers: Reduces the coefficient of friction at the clutch pack interface. The LSD clutches slip rather than engaging positively, reducing locking force and causing accelerated clutch wear. Not suitable for clutch-type LSDs.
• Cusco LSD-specific oil: Formulated without the friction modifiers that suppress clutch engagement. Maintains the correct friction coefficient for positive, consistent LSD ramp engagement and normal clutch pack wear rates. Use of the correct fluid is required to maintain the LSD’s rated locking characteristics and service life.

80W-90 Viscosity — GL-5 Specification

80W-90 is a conventional gear oil viscosity grade — slightly thicker at operating temperature than 75W-90 (more common in modern synthetic formulations). API GL-5 is the gear lubricant specification for hypoid differential gear sets that operate under high pressure and shock loading — the standard specification for rear differentials. Note: GL-5 oils are not suitable for most manual transmissions with brass or bronze synchros due to the sulphur-phosphorus extreme pressure additives — this oil is for differential use only.

Mineral Base — Change Intervals

This is a mineral (conventional) base oil, not synthetic or semi-synthetic. Mineral-base LSD oils have shorter recommended service intervals than full-synthetic equivalents — typically every 20,000–30,000 km in normal use, or every 10,000–15,000 km in performance, track, or high-heat applications. Some Cusco LSD units specify mineral oil for the initial break-in service interval before transitioning to synthetic fluid. Confirm your specific LSD unit’s service recommendation in the Cusco documentation.

Application Guidance

Suitable for: Cusco clutch-type and plate-type LSDs in RWD and 4WD rear differentials; open rear differentials requiring GL-5 80W-90 specification fluid; any rear differential application where 80W-90 GL-5 mineral fluid is specified. Sold as a 1-litre bottle — check your differential’s fluid capacity (typically 1.0–1.5 litres for a passenger car rear differential) and order the required quantity before draining the existing fluid.

LSD-specific fluid — use in mechanical LSD-equipped differentials only (not standard GL-5 replacement). Mineral base — shorter service interval than synthetic. Not for manual transmission use. 1 litre per bottle — confirm your differential capacity before ordering.

Specifications

• Brand: Cusco
• Part Number: 010 001 L01
• Type: LSD differential oil
• Viscosity: 80W-90
• API rating: GL-5
• Base: Mineral (non-synthetic)
• Volume: 1 litre
• Application: RWD and 4WD rear differentials — clutch-type / plate-type LSD and open differential