SAE 90 weight hypoid gear oil is required. If equipped with Traction-Lok differential, the addition of friction modifier additive C8AZ-19B546-A or equivalent, is also required when draining and refilling.
See Figure 1
Checking the differential fluid level is generally unnecessary unless a leak is suspected.
- Raise and safely support the entire vehicle on jackstands. Refer to the Jacking procedure in this section.
- Remove the oil fill plug from the differential housing. The hex drive on a 3 / 8 in. drive ratchet, breaker bar or extension works well on most applications.
- Insert a finger into the fill hole; be careful as the threads may be sharp. The oil level should be about 1 / 4 in. (6mm) below the bottom of the fill hole.
- If the oil level feels low, add oil through the fill hole. Most hypoid gear oils come in squeeze bottles equipped with small fill nozzles, designed for this purpose.
- When the oil level is correct, install the oil fill plug and tighten to 15-30 ft. lbs. (20-41 Nm).
DRAIN AND REFILL
See Figures 2, 3, 4 and 5
The differential should be drained and refilled every 100,000 miles (161,031 km) or if the axle has been submerged in water.
- Raise and safely support the vehicle on jackstands. Refer to the Jacking procedure in this section.
- Clean all dirt from the area of the differential cover.