So I had a bearing fail on my 65 truck, 9 inch, 28 spline. Bought the bearings (changing the left and right, $75 each) and had someone else press off and press on the new. These are roller bearings and sealed on both sides. I am thinking why, why are they sealed on both sides of the rollers. How will the differential oil get down the tubes to lubricate these bearings if they are sealed ? Is it a good idea for me to pop the inner seal out of each bearing so oil can help lube them ?