Checking Fluid Level: Differential
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 1992 Toyota Tercel, 1992 Toyota Supra, 1992 Toyota Paseo, 1992 Toyota MR2, and 1992 Toyota Cressida. However, it is still accessible from the selected car via links, so may be relevant.
Remove filler plug. Fluid should be level with bottom edge of filler plug hole. If fluid is level with opening, install fill plug. If fluid is low, fill until fluid is level with fill plug opening.