My rear factory rubicon locker just failed after 15 years, not sure how the first owner treated her, but the last few years have been some hard rock climbing and I did constantly lock and unlock when on the trail, so in my opinion it is reliable. Not sure what actually failed, all I know is that the housing was full of metal pieces. I drove it home from the trail after failure and lucky for me no damage to the R&P or axles, but metal did get into the carrier bearings and tore them up pretty good. I replaced with Eaton ELocker, 19977-010 (which is for 3.73 and under, but the Rubicon uses thicker 4.10 ring gear so you want the 3.73 and under carrier), and it was a pretty simple install. Ran the wires through the factory air hole (using plenty of RTV) and then I pipe plugged the factory switch hole (think it was a 1/4" NPT, I had it laying around). Still have to run the wiring and install the switch and then hopefully will have her back on the trail the following weekend. Heading to Hawk Pride in AL and then up to SMORR in MO in March.
I did consider installing a front factory rubicon locker in the rear, but the cheapest used front I could find local was $750 and non-local was $500, and I was able to find the Eaton at a really good deal, so figured new would be better. Also, I plan on keeping the rear pump and all the factory rear air hose installed so I have them as a spare for the front if needed in the future.
With the replacement installed, I'm fairly certain the original rear was damaged when I bought it. There were times when it was really stubborn to lock, but this one is quick and predictable like the the front is.
