Subaru 75W-90 Gear and Transmission Fluid 1 Quart OEM SOA427V1700 — Extra-S reduces 3→4 shift grind

Subaru 75W-90 High Performance Gear and Transmission Fluid (Extra‑S) is the factory‑specified lubricating oil used in Subaru transmissions and differentials, now available in a convenient 1‑quart OEM bottle.

Designed for Subaru models that call for 75W‑90 gear oil, this Genuine OEM SOA427V1700 formulation was engineered to protect gears, reduce shift effort, and help minimize the common 3→4 shift grind reported in higher‑mileage 5‑speed WRX transmissions. Previously offered only in bulk drums, the quart packaging makes it practical for DIY maintenance, top‑ups, or small repairs while retaining the exact specification Subaru recommends.

How does this fluid improve shifting in older WRX/STI transmissions?

The Extra‑S 75W‑90 formulation contains friction modifiers and additives tuned to Subaru gear trains, which smooth engagement and reduce metal‑on‑metal clatter during gear changes. Drivers have observed noticeably easier shifts and fewer occurrences of grinding between third and fourth gears after replacing with this fluid.

• Contains additives to improve shift feel and reduce gear noise
• Maintains consistent viscosity under load for reliable engagement
• Helps reduce wear in higher‑mileage transmissions
• Matches Subaru’s factory specification for OEM consistency

Will this 75W‑90 work for differentials as well as transmissions?

Yes — Subaru specifies this Extra‑S 75W‑90 for both manual transmissions and hypoid differentials where that viscosity is required. The formulation provides the shear and pressure protection needed for gearsets operating under heavy loads and sliding contacts.

• Suitable for manual gearboxes and limited‑slip differentials requiring 75W‑90
• Provides extreme‑pressure performance for hypoid gears
• Compatible with Subaru seals and gaskets when used as directed

How much fluid do I get and when is a quart the right choice?

This listing contains one 1‑quart (946 mL) bottle of Subaru Extra‑S 75W‑90 gear and transmission fluid — ideal for partial fills, drain‑and‑refill services that don’t require a full system capacity, or topping off after a service. For full gearbox overhauls or multiple vehicles, larger quantities may be more economical.

• 1 quart bottle for convenient home or shop use
• Perfect for top‑offs and single‑service refills
• Buy multiple quarts for full drain and refill procedures

Is this the same fluid Subaru uses from the factory?

Yes. This product is the Genuine OEM Subaru Extra‑S 75W‑90 gear and transmission fluid (SOA427V1700), formulated to Subaru’s specifications. Using the factory‑specified fluid ensures compatibility and maintains the intended shifting characteristics engineered into Subaru drivetrains.

• Genuine OEM Subaru part number SOA427V1700
• Formulated to meet Subaru’s original specifications
• Recommended for maintaining factory shift feel and longevity

Who is this for: Enthusiasts, independent mechanics, and Subaru owners who want the exact factory fluid for manual transmissions and differentials will appreciate this 1‑quart Genuine Subaru Extra‑S 75W‑90. It’s especially useful for WRX/STI owners addressing shift‑feel issues in older gearboxes, anyone performing routine maintenance without bulk supplies, or those who prefer OEM components for preservation of vehicle performance and value.