I know this is a problem of me not being able to use proper search terms or have the patience to sift through a million search results to find what I need, and not a lack of this being talked about before. So bear with me...
My hub(s) aren't grabbing in the auto setting anymore. Still no problem with them in lock, but it's getting to the time of year when I only need 4x4 now and again, and usually only grab it when I actually need it and am almost stuck, so it kinda sucks to switch to 4x4 and still be in 4x2.
So my main question... how long do I have before they stop grabbing in lock? I hear reference to these being vacuum actuated. Are they? If so, is this likely a failure of that system, and what are the typical weak points?