What type of rear differential fluid does the 2003 chevy silverado use?

The 2003 Chevy Silverado uses 1.83 quarts of SAE 75W-90 gear oil in the rear differential. This is the best fluid for Your differential because the thick oil offers excellent protection for the gears. The rear differential is the last place that power from Your engine goes before it reaches Your back wheels. It is important to keep the gears in this area lubricated so that they stay working. If they fail You will likely lose power and not be able to drive. 75W-90 gear oil is ideal for a differential as well because the volume is so small so the area gets hot. The thicker oil will not break down under the heat like a thinner oil.