Excessive differential oil
Worn or defective oil seal
Clogged air breather
Loose differential carrier bolt
Defective differential carrier liquid gasket
Loose or damaged pinion flange
Loose filler plug and drain plug or defective gasket
Defective gasket of the filler plug and drain plug
Clogged air breather
Axle case cracking
Loose differential carrier bolt
Defective differential carrier liquid gasket
Worn or defective oil seal