btw - this is only good for wheel bearings, and not the actual drive joints. You need a moly grease for them. Same with driveshafts, this grease is ok for the U joints but not the slip yokes, you need moly grease for that.
If you see that only the cover is leaking then reseal it with some HD RTV sealant that can resist gear oils, like Toyota FIPG or threebond 1207B. Make it very clean first, then wipe with acetone - install and tighten down properly.