GM DEXRON III F

GM DEXRON III F is a General Motors approval for automatic transmission fluids that sets requirements for viscosity, thermal stability, friction properties and oxidation protection, as well as compatibility with seals and metal surfaces of gearboxes. The specification provides a stable viscosity in the range of 3.5–5.0 cSt at 100 °C, high resistance to dissolution and a controlled friction characteristic, ensuring smooth shifting and preventing premature wear of gear teeth. DEXRON III F is used in 4‑speed and 5‑speed automatic transmissions (4L60‑E, 4L80‑E, 4T60‑E, 4T80‑E) in passenger, off‑road and commercial GM models produced up to the mid‑2000s. Because it is a transmission oil, it contains no sulfate or phosphate additives, making it compatible with catalysts, but it is not intended for DPF systems. If necessary, one can switch to newer GM approvals DEXRON III H or DEXRON VI, which retain the core requirements of DEXRON III F, however the manufacturer's replacement recommendations should be followed.