[rotorwrench]

The recommended lubricants are dictated by the manufacturer. Outdated lubricate grade ratings generally always have a modern equivalent. Seal technology back in the early automotive era was not as good as it is today but it kept the majority of the lubricant inside where it belongs. It's after the seals deteriorate and clearances wear when it gets harder to keep the lube in. Renew the seals and seal up any clearance gaps and the units should still hold their mud.