Originally, Dodge recommended that a mixture of 2 parts 600wt steam cylinder oil to one part medium grease be used, creating a semi-fluid grease. This 600wt oil is available from aftermarket suppliers, HOWEVER, after consulting with lubrication engineers, i have found that there is a modern equivalent to the home-made semi-fluid grease. The 600wt oil is, in modern units, an ISO VG 460 oil. After contacting Exxon-Mobil's lubrication consultation service, they do make a semi-fluid grease, NLGI 00 (which is semi-fluid) in an ISO VG 460. It's Mobil SHC 007. It's designed for, among other things, old gearboxes, leaky gearboxes, and steering gears on large trucks. It has an EP additive which is needed in gearboxes.
Can be bought in a 5 gallon pail, otherwise known as a 35lb keg at amazon, or other place you can buy bulk oils. Here's a link that hopefully wont go dead like most forum links.
http://www.amazon.com/dp/B00G97ECX4/ref ... T2F5G87711