2006 f350sd 6.0 5500miles I switched to 4wd, and the light and the action seemed to take about 3 minutes. I was moving a heavy tailer in the yard so i switched to 'low range'. It didn't do anything. I got out and dumped the trailer...about 5 minutes... and when I got back in the truck, it was in low range... I pulled up and then switched back to 2wd.. nothing.. I turned left and right as i pulled up, in case ther was a bind on the gears. Went to neutral. Backed up. left then right. stopped engine restarted..etc. you get the drift, tried everything. I came inside. As far as I know, it's still in 4wd low I bet that will kill my mileage when on the interstate. j/k
Any suggestions? It's like it will only engage/disengage if you're not watching it, or when you turn your back.

 

it will only go in low when in neutral, in drive it wont go

 

like stated above, low range will not engage unless you are in neutral. If you 4 hi is responding slowly, you may have a vaccum leak or something else wrong. If that is the case, I would take it to the dealer and have them check it out.

 

I think y'all are right about the neutral thing. I went out today a played with it a bit, and it seems there is just some combination of events that have to happen to get it to engage/disengage. A friend told me that his is quirky, too. My last truck had a lever on the floor and it was self-explanatory. Thanks so much for the quick responses.