Originally Posted by 80cj
Use a mixture of grease and gear oil blended together. Use your wifes baking mixer to blend it.
Or you can fill the knuckle with the ingredients and simply drive around for a couple of minutes with the hubs locked in.
Do yourself a favor and pull the knuckles apart. Many times they are run dry for years, ruining the upper and lower kingpin bearings, as well as the axle u joint. This also gives you a chance to clean up the seal surfaces in order to keep the fluids inside.
The seals are still available and are relatively cheap. Don't be afraid to replace them.