In the 50's we had two types of grease; soap based grease and the fiberous grease that was used in wheel bearings. Neither one of them was recommended for U joints. Alemite and probably other manufactures made a pump that would pump mineral oil under pressure. Oil was carefully pumped into the fitting. Care had to be taken to keep from blowing the seal. We lubed our vehicles once or twice a week in the 50's. Those days are now long gone. We use moly grease in our U-joints and grease them every 25,000 miles. There is no such thing as big truck hub oil. The few trailers that still run oil use plain old gear lube. Semi fluid synthetic such as Mobil Lith 007 has pretty much the standard of the industry. Unless a seal goes out, we remove the hub caps about every 50,000 miles and pump in about a 1/4 of a cup full into the cavity. On our newer equipment, we now use Spicer SPL U joints that carry a 100,000 lubrication recommendation.
http://www2.dana.com/pdf/J3295-2-DSSP.pdf
