See Figures 1, 2, 3 and 4
Drive axles are traditionally identified by the shape and number of bolts attaching the rear cover. The drive axle is originally equipped with a gear ratio identification tag attached to the rear cover by one of the cover bolts. However, this tag is easily misplaced and may no longer be attached to the cover.
To identify the rear axle ratio, simply count the number of teeth on the ring gear and divide that number by the number of teeth on the pinion gear.