By putting 1/4 quart inside the boot/can, it fills it high enough that the center shaft and over half of the spider are submerged in oil.....when it spins that oil will be thrown all over the assembly by the ribs in the spider.....I doubt there will be any lubrication issues....if the old grease had turned to liquid and worked for so long, then I bet good gear oil will work just as well.

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