Ramcharger vibrates after using 4wd

Check the vacuum lines from the t-case to the front axle. I’ve had those vacuum cans rust out and/or lines crack and have had the fork not move all the way back. I used to put manual lock outs on my CAD axles for piece of mind!
Thanks, I will check that out. I'll look at all the vacuum hoses. Another area for me to look at. My dash light says it's not engaged, but that's not saying it's not still in.
Thanks!