The order would be: the inner oil seal, then the axle shaft and bearing with the bearing cup in the axle housing tube. Then the shims go in place, next a gasket, then the retainer in question, then another gasket. The brake backing plate is next, and then the outer oil seal. The retainer holds the axle and bearing in place. Only one side has shims. The shims are for axle shaft end play. The retainer is to hold the shims in place as well as the bearing cup in the housing. Hope this helps. The rear axle assembly is a standard Dana/Spicer unit. Check your service manual or parts manual for a diagram of pieces in order. The service diagram shows the shims on the right side. Other vehicles show the left side.
