While doing some cleaning in my Argosy, I re found the Dexter service manual for the axle I had installed a few years ago.
I looked at again and found it to be a very very good source of information on everything axle related, from brake magnets, to wiring diagrams, to grease types and qualities, bearing numbers for all Dexter axles , how to lube the bearings and on and on.
I have a paper copy, which is great, but I looked on line and found that they have a PDF version that you can download for free. I didn't search to see if they will send you a paper copy, they may.
This is good, complete information on axles from 600 to 8000 pound capacity.