What is the toyota tacoma rear differential fluid?

Toyota recommends that You use 75W90 gear oil any time that You need to replace the fluid in Your rear differential. You should also change this every 30,000 miles to help protect the gears back there. The differential is the laSTSet of gears that the power goes through before it reaches Your rear tires. It is a small area so a much thicker oil is used because it can handle the heat of being in a small area under pressure better than a thin oil. If You notice anything leaking from Your rear differential You should address it as soon as possible because low fluid levels cause the gears to grind and break.