I won't curse you...it's just a learning thing...but it is important to have the locking ring installed. That ring holds the end of the axle in place in the diff (especially over bumps).
Did you get the old ring out? You don't want any little bits of metal running around in the diff. (that's one good use for those $5 telescoping magnets)

I don't know about backing off the nut, 'cause I don't know how tight it is.
For future reference, the way I would do the job from the start is to count the # of turns when removing it and try to put it in the same # of turns. At the point you are at it is a little harder to determine how tight the diff is. As I said before, that nut is a backlash adjuster.
There is a procedure for checking it but you would need a dial indicater. I can go thru the whole thing if you want.
Basically it's probably ok if you can take the front driveshaft (from the transfer case to the front diff) and rock it back and forth, with your hand...there should be a little play (a little sloppy) If it is tight and wont move at all...we need to go thru the procedure to check it.
Don't hesitate to ask if you wanna do it and you have the dial indicater

 

Thanks for getting back to me... Im really sorry that i havent come back with an update. Ive had to put my front diff problems to teh side-she blew a headgasket tonight :-(

I bought a front diff just in case-anyone want one? Could anyone tell me what it would be worth?

thanks

-Michael