I do believe they are made from a rare rust-able tin foil. 'tis the bane of MJ owners everywhere.
are you re-torquing the nuts after a drive around the block?
how hard do you need to pull on it to get it to engage? I could see myself maybe fabbing a bracket that attaches to the center console in my truck. you could tie in to the 4wd shifter bracket for strength.
the difference in MPG is essentially whatever it takes to spin the driveshaft around. very tiny compared to pushing a 2 ton brick through the air.
after the aforementioned items, I would then do all of Cruiser54's MJ tips and the headlight relay. should be links to both in here:
https://comancheclub.com/topic/13447-what-is-the-most-important-tip-youd-share-with-mj-owners/
Jeep stopped using the CAD in the early 90s. no one has found any extra wear and tear in those XJs over the CAD MJ/XJs . no change in MPGs either. sounds like it was mostly an advertising gimmick more than anything else.
but keeping it gives the option of 2wd Low range if that appeals to you.
jogged a little today (like 20 yards) just to see if I could. no pain at all from that. yesterday I lightly kicked a soccer ball back to my nephew and got that intense stabby pain on the side of my knee that put an end to the fun real fast. not sure what to make of it all other than I'm more healed than before but have a ways to go.