The OP said clutch so I'm assuming a standard.
Originally Posted by Badfish
leave tranny in neutral no clutch, if you are going into 4hi be moving below 40 mph and if you are going into 4lo then be moving under 7mph. i found it is easier to be moving while changing into 4wd then doing it while standing still. just my 2 cents hope it helps
I have tried the method that Badfish said but find it difficult to do especially on the trail.
If I'm traveling on a trail or in snow, if things appear to be getting sloppy and the jeep is slipping as can be felt by moving about the center axis of the jeep, I will shift to four on the fly by just putting the clutch in and moving the lever back. The times that I have done that it has been easy to do.
Over rough terrain on the trail is slightly different. I have many times been in 2wd and come up to a particularly difficult spot. I would then go to neutral with the clutch in and shift to 4H at a stop. If needing to go into 4L at that point, I shift the TC into neutral and the gears never seem to line up where the shifter can be moved easily into 2L. If having difficulty getting it into 2L, I put the tranny back into 1st then, while applying pressure on the TC shifter towards 2L, I carefully let up on the clutch to nudge the gears and it just drops right into gear without much pressure at all applied to the shifter. As soon as you can feel it dropping into gear I then go back onto the clutch and finish the shifter movement.
I did break the linkage once shifting into 4L because it was just very difficult to move from 4H into TC neutral. That is why I'm going to be a lot more careful coming out of 4H into TC neutral by doing it with the tranny in neutral and the clutch in.
When I broke the linkage (60 cent part) I was pretty nerved up because of the situation I was in. Lesson here was to pause and think about what you are doing before doing it. Just in case I make the same mistake again I carry three of those 60 cent plastic bushings in the glove box now. I don't want to be stranded in the middle of nowhere unable to shift the transfer case on demand.