After I installed my new right rear spindle I decided to convert it to oil bearings. Before I installed the inner bearing I filled the hub with 60 weight engine oil then installed the inner bearing and seal. Then I made a tool that allowed me to put even more oil into the hub while the trailing arm and hub assembly hung down at a 15 degree angle. Then I filled my left spindle hub with oil. I estimate they each hold about 10 tablespoons of oil or about 5 ounces. To prevent pressure from pushing the seals out I drilled a .020" hole thru the tops of the inner seals. I'm did this as an experiment only but if it doesn't present any problems I'll leave them like this.