That is true. I would recommend warming the transfer case up either storing it in a garage running it for a while or a torpedo heater. Before switching to Synthetic gear oil I would have problems in temps below 25F. no matter what, he is definitely going to have to put some muscle into it.

Richard E
1989 Montero - Stock-ish
1989 V6 Auto Raider - 5.3 Vortech Swap.
1987 Mitsubishi Starion 2.6t, soon to be 3.5
1983 Honda XL600R