Grease Options for OTC DR4000

I recently purchase an old OTC DR4000 welding robot. I am trying to find grease for joints 4,5&6. The maintenance manual calls for Harmonic HC-1A which after talking to Harmonic isnt available anymore. They recommended Multitemp AC-N, however that is only available in 2.5kg and is $500, when I only need about 40 ml. Anyone know of a comparable grease to the Multitemp AC-N?