2017 Ram 3500 Transfer Case

You can shift into 4Hi on the fly. 4Lo needs to be from a stop in neutral. If You are stuck and only the rears were spinning you should stop them first before shifting. I don’t think the transfer case will allow the shift To 4Hi unless all wheels are travelling at the similar speed.

Camp n family is correct .On my truck I also must be completely stopped to take it out of four low !

As they said. You dont want the rear wheels spinning when shifting it and of course you have to be stopped for low range.

I found the diesel supplement . to be helpful

NJRVer wrote:
Says don't shift transfer case if only one set of wheels is moving. I would take that to mean if you are stuck in 2wd don't shift into 4wd while you are spinning the tires.....

I think this is true for any transfer case. We were at the boat ramp and this lady backed in a trailer with a Jeep Cherokee. The husband runs the 22' boat on the trailer, she starts up the ramp, and the back wheels break traction as soon as the boat sets on the trailer. She guns it with tires squalling and he's back in the boat screaming for her to put it in 4 wheel drive. She can't hear and keeps doing a burnout and he keeps screaming louder.

Finally she looks back and hear's him screaming then reaches down for the T-case shift handle while doing a really nice burn out. KKKKAAABBLLLLOOOOMMMM :S :?

The whole driveline lurched and instantaneously came to a violent stop. We didn't stick around because I knew the pending alcohol fueled argument was going to get nasty and we had small kids with us. However, I'm sure the T-case had to be completely obliterated after that ordeal.

So, there's a real world example of why not to shift into 4X4 when the two drive shafts aren't both spinning.

KJ

It's perfectly fine to go from 2 hi to 4 hi (and back again) while moving but you want to be coasting at the time.
So let off on the gas, shift and resume.

Thanks everybody.
I figured it was ok, but wanted to double check.

Different year but for what it’s worth my 2012 says shift into 4low in neutral stopped or ideally in neutral rolling less than 5mph.

campigloo wrote:
Different year but for what it’s worth my 2012 says shift into 4low in neutral stopped or ideally in neutral rolling less than 5mph.

Yes, that's always the case with using a different range.
Trust me, you don't even want to be doing 2 mph. Did it once when I wasn't concentrating and it made a horrible clunk.