I'm sure you've seen the news about the guy who flat towed his Jeep, leaving it in 4LO and 1st gear. I was actually towing mine to the Shenandoah valley when the story broke. I always triple check. I first make sure that when I put in D, it won't go forward. I check that the 4wd light is not on. Then before hooking up the tow bars I make sure the Jeep can roll back & forth. I have learned in my 2014 that I don't need to leave the key in the ignition, even though the manual says to do that. At some point the jeeps stopped using the steering wheel lock.

 

I saw the pictures of that catastrophe. That was insane.

For anyone who missed it:
https://www.thedrive.com/news/39794/...ng-it-in-4-low

 

Yeah - semi-circular wheels on one I saw once!!

Best way for manual or auto is to put the vehicle in gear engine running and try to move it after it is hooked up. If the TC is in N like it should be and the vehicle does not move then it is good. Auto should be left in P and manual in any forward gear to prevent the gears spinning. TC has a small output shaft driven oil pump which lubes the gears as it is being towed.