Oil Seals Rear Axle

[buckled wheel]

put new wheel bearings in hilux rear end, a while later oil is coming out of brake drum. take it too bits,and find when cornering the oil is washing up the half shaft, washing the grease out of the bearing, and running down the wheel. a new oil seal goes in , still the same , onto toyota 4 times they cant help. one bloke says take diff out, remove small plate, theres a seal inbehind. no theres not!!!! after sending me two seals the same, they send me a different type. the oil is only coming out the drivers side , not the passenger side which has the original seal in!!!!!!!!!!????????? the bearings etc are all in ok, nothing worn cracked or marked. why is the oil only coming out one side????? anyone else had this prob, on 1994, 2.4 td hilux.LN model. thanks...