Im just finishing up On my YJ with a Bronco dana 20 and need to know what to do to flat tow it behind my motorhome --- will I have to disconect the driveshaft or is ther some oil mods to do.......................

disconnet it

For short distances you can put the t-case in neutral, but leave the front hubs locked. The turning front output will keep everything lubed. For motorhome distances just spend the 5 minutes to disconnect and tie up the driveshaft.

Thats what I found with some other searches Ive done THANKS for the info

Not that I'm advocating this way, these are just my experiences.

I have a twinstick EB dana 20 in what else, my EB. I have towed for several hundred miles without disconnecting the d-shaft. I left the case in 2wd, and popped the trans in neutral.

By having it in 2wd, the rear d-shaft was turning the rear output, the countershaft, as well as the front reduction gear set (although it is disconnected from the front output by a shift collar, it still turns via the countershaft). I figure the climbing action of the gear oil lubes the t-case the same this way as it does driving down the road in 2wd.

Think about it... the input shaft and the rear output are turning. This is no worse than driving in 2hi. Same exact thing as far as the t-case is concerned.

So the only thing to worry about is the tranny. And since I believe that will be turning its coutershaft as well (NP 435), it should be lubed up just like when its running.

So far it has been a-ok while flat towing, and no problems whatsoever. I've got a trailer now so it's a non-issue, but these are my experiences.

Basically, from what I see, the trans and t-case don't care what side the "power" is coming from, just as long as all the same parts are moving while towing as do under normal driving situations.