If the bearings are cleaned up and look good, don't worry a bit about the outer seal that is in the retainer. It is a dust seal to keep dirt, moisture, and brake dust out of the bearing area more so that a grease seal. You will have to pack the bearing with a good wheel bearing compatible grease and remove and replace the inner seal that keeps the rear end lube from the bearing area. There should be no rear end lube entering the bearing area on an 8 3/4 rear end. Use the axle itself for the puller. There is no special tools needed and removing the seal is easy and is done in the same step as the axle is removed from the housing. Just hole the axle toward the rear ov the car and have the spline d end rub on the housing as you remove the axle, when you feel it touch the seal give a pry back and the seal should come out on the end of the axle. works great and takes a couple of times to get the feel. The only time the outer seal is replaced is when the bearings are replaced and if the bearings are good there is not reason to replace them.
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