Differential (Prizm)
WARNING: This page is about a different car, the 1989 Geo Tracker and 1989 Geo Prizm. However, it is still accessible from the selected car via links, so may be relevant.
Differential ATF reservoir is separate from transaxle fluid reservoir. Remove differential fill plug in middle of pan on side of transaxle differential housing. Level should be at bottom of fill hole. See Figure.