As I said, if the transfer case is in neutral, the upper bearings may not be sufficiently lubricated. It isn't because only two wheels are turning, it is how the transfer case is turning. It is just easier to take a 10mm wrench, a roll of duct tape, and a bungie cord with you.

For short trips, you shouldn't have any issue if the transfer case is in neutral (transmission in neutral for good measure), but for any extended towing, either flatbed/trailer or disconnect the rear driveshaft.

 

If you are renting a dolly from Uhaul, just spend the extra $10 and get the flat bed car trailer. I will save you time and will be sure not to screw up your truck. As far as the jeep pulling it, it should be fine, its got a v8 and some decent axles. Just make sure its a class3 or higher hitch and check the tow ratings (from a quick search on edmunds, i found that a 1996 grand cherokee with the 4.0LI6 has a max of 5,000 pounds, which with the blazer and a trailer would be darn near that, so I would say you should be fine).

 

thanks swartlkk for expalaining it better lol. Wasn't entirely sure and I suck at explaining things.

 

No problem! That's what we're all here for, to make sure that the OP gets the required information!!