VP Racing Classic® Hi Performance API GL4 SAE 80W90 Gear Oil

VP Classic GL4 SAE 80W90 Gear Oil is formulated specifically for classic manual transmissions that contain yellow metals. Brass synchronizers, bronze thrust washers, copper bushings, and similar soft metal components are common in vintage American and import manual gearboxes, and they require a GL4 specification oil to stay protected.

Why GL4 matters for classic transmissions: GL5 gear oils contain higher concentrations of extreme pressure additives, specifically sulfur-phosphorus compounds, that can chemically attack yellow metals over time. Using GL5 in a transmission designed for GL4 can cause synchronizer degradation, rough shifting, and accelerated wear. VP Classic GL4 delivers the correct protection level for these applications without the chemistry that damages soft metals.

Compatible Transmissions

VP Classic GL4 80W90 is recommended for:

• Muncie 4-speed (GM)

• Borg-Warner T10 and Super T10

• Ford Toploader

• Saginaw 3- and 4-speed

• Rockwell manual transmissions

• Import manual transmissions and transaxles calling for GL4

Features & Benefits

• GL4 specification, safe for brass, bronze, and copper components

• Special anti-wear additives prevent scuffing and welding on gear contact surfaces

• Delivers outstanding wet clutch performance

• Long-lasting inhibitors protect against corrosion, rust formation, and foaming

• Maintains gear cleanliness for consistent shift quality

• Improves shifting feel and reduces transmission noise

Frequently Asked Questions

What is the difference between GL4 and GL5 gear oil? GL5 contains higher concentrations of sulfur-phosphorus extreme pressure additives that can chemically attack yellow metals like brass, bronze, and copper. Most classic American and import manual transmissions use these metals in synchronizers, thrust washers, and bushings. GL4 provides the right protection level for those components without the damaging chemistry. Always match the oil specification to what your transmission manufacturer requires.

Can I use VP Classic GL4 in a differential? No. This product is formulated for manual transmissions and transaxles requiring GL4. Do not use it in applications requiring GL5 extreme pressure gear oil, limited slip differentials, or any application calling for an OEM specialized lubricant.

What transmissions is VP Classic GL4 compatible with? It is recommended for Muncie, Borg-Warner, Ford Toploader, Saginaw, and Rockwell manual transmissions, as well as import manual transmissions and transaxles specifying GL4 gear oil.

Is VP Classic GL4 safe for synchronizers? Yes. The GL4 specification is specifically chosen to protect synchronizers made from yellow metals, which are common in classic manual transmissions. GL5 oils can damage these components over time.

What size does VP Classic GL4 come in? Currently available in 1 quart.