In an effort to hedge against the inevitable water in the actuator do you think a quarter ounce or eighth of an ounce of pink antifreeze would harm the actuator?

 

I don't know what effect antifreeze might have on the seals. If I was determined to put something in there, I think I'd use some kind of water soluable oil, like that that is used in machining.

 

I was thinking a good shot of WD 40 or something. I'm also concerned with freezing water. Hub problem shows up when temperature is below freezing. Perhaps both is a good idea.

 

Why is it inevitable that you will get water inside the actuator?

When parked, vacuum bleads off and in the morning the actuator is engaged anyway, start engine, vacuum builds, then it disengages unless started in 4WD mode.