Bolt that attaches drive shaft to transfer case flange (one of the few that are used on that end). If I take it out I have access to one of the grease fittings. It's still tight but doable, at least for me.
Other than that one fitting, all the other ones are pretty well accessible. I have 11 grease fittings between both shafts.
Once again I have 1350 shafts, so I changed both, flanges and yokes