Run thicker oil in the final drives is my tip, once you start tacking bits off a old Cat you open a Pandora's Box that is invariably followed by divorce and or bankruptcy.😆😆
Search the history section here on ACMOC for background info as D2's final drives are often discussed, you need the right tools and the time to get it done assuming you only do the seals, and not the brakes and steering clutches too, contact Paul Moore or Tillys up at Toowoomba for the seals, they have the best prices in southern Qld.
regards
Mike
be sure to check the play in the sprocket spline--if worn you may need to add shim washers under the sprocket nut.