The rear differential in a Saturn Vue requires 75w-90 gear oil that contains a limited-slip additive. This fluid should be changed at 30,000-mile intervals in order to preserve the life of the unit. The fluid level must also be checked periodically in order to prevent damage to the internal components. The rear differential does not contain a dipstick or measuring device. Checking the fluid requires access to the underside of the vehicle.
Place the vehicle in park and chock the front wheels. Raise the rear of the vehicle and support it with jack stands.
Crawl underneath the rear differential and find the fluid fill plug on the right side of the differential housing.
Remove the fluid fill plug using the 3/8-inch ratchet.
Place your finger inside the fluid fill hole. When full, the fluid should be level with the bottom of the fill hole.
