FINOCJ previously posted:
"I don't know about the JL jeeps per se, but on the previous TJ Rubicon models, there is a pretty easy modification that lets the locker switches activate in 4hi....and I think it also over rides that the rear must be locked before the front. It's been over 10 years, but it was on of the first mods a friend and I did to his TJ...think it took about 30min to reconnect a couple wires at the switch and fusebox."
Ah yes, this is a "hidden" feature on at least the '21 and '22 JL. In order to lock the rear in 4Hi, you hit the Offroad+ button (this turns off the traction control, the light gets lit up), then hold the traction control disable button for about 5 seconds until the gauge cluster says something like "Electronic stability control disabled" then you can lock the rear. I ran with the rear locked pretty much all day today. I don't mind an extra wheel spinning up some of those hills.