Differential Unit problems of the 1996 Toyota 4Runner

Differential/axle housing rusted out. I purchased the truck this past week and noticed a significant amount of rust on the differerntial housing and where the suspention parts connect to the housing. This is what holds the differential/axle assembly to the truck. If left unchecked the cover wwill eventually rust out and leak oil and could potentially lead to a crash if the diffeerntial locks up due to no fluid. Also the brackets could rust out causing the suspention parts to break away from the housing causing a crash. This is a know issue on 4runners and well documented on many internet forums.