Off Topic Arrow Gear Multi Disc Friction Reverse Gear Box HELP

Have not been around this forum much since I completed the restoration of my D2. Since then moved on to other projects. However I recognize the wealth of mechanical information that exsists among ACMOC members and the followers of this forum. Have a 30,000# Braden winch mounted on my Lowboy trailer that is driven by a Wisconsin V4. Between the engine and the winch I have an Arrow Gear Multi Disc Friction Reverse gear Box Model FRH 61B. This gear box has started to slip pretty good, rendering the whole unit pretty much useless.. I needed to do some revamping of the winch assembly, so today removed the engine and this gear box. There is an internal clutch adjustment but I can't seem to figure out how it works. A web search didn't turn up much other than Arrow Gear was absorbed into Braden industries and they spun off their winch Division to Paccar. This unit is by now pretty much obsolete and does not have any factory support anymore.

Anyone out there have any experience with these and/or perhaps any operation/maintenance instructions?? (some where I did round up a parts list and schematic for this unit)

Thanks D2Denny