Thanks for this insight.

I am at 80k miles on a 2011 LTD in Upstate NY. I recently lost some (1/2 litre) fluid out of the driver side front shock XREAS while putting in a Daystar spacer (newbie mistake). Living in the rust belt, I know I'm coming up on the end of life for them, so am curious what signs you noticed so I can know when I ought to to replace them. Feels fine, but, after reading all these posts about removing it ASAP once air gets in, I'm paranoid and noticing every bump. Sounds like 5100s are the way to go, but I hadn't budgeted for replacing this system, so hoping I have a few months to save up.

You're welcome!

Although this thread is in the 4th Gen section, the issues/problems with the X-REAS will become similar for the 5th Gen. My 2011 Limited also has this suspension system, so at least I'll be better prepared if/when the system fails.

The corrosion certainly is a worry of mine as well - just be sure to keep inspecting those fluid lines whenever you have your vehicle in for routine service or up on a hoist. Frequent rinsing of the undercarriage during the winter months to get the road salt off will help.

The ride does get noticeably rougher once fluid has leaked out of this closed system. But it was the visual of seeing the fluid in the driveway that clued me into something being wrong. It is a good idea to park in the same spot at home, and when pulling out have a quick look to see if there is any fluid on the ground (whether it be this suspension fluid or leaks from other places).

I was dealing with a "catastrophic" failure that needed immediate repair, which did not give me the luxury of doing good research and shopping around for a good deal. You seem to have some time on your hands to both plan for what you want next, and to save up some $ to do it.