HELP!    I am rebuilding an older CJ5 with a rear Dana 44 and some type of locker. The axles are 19 spline. The locker has two collars on each end of the carrier that each axle must slip into for re-installation. Hence, the collars must be aligned to accept the re-installed axle shaft. One of the ends on the drivers side has become misaligned and the axle will not slide in. How can I re-align these two collars?  

If what you are reassembling is similar to a detroit EZ Locker the two collars should not need to be lined up.  you should be able to spin the axle shaft until it lines up. What may be happening is that you are hitting the bearing at the end of the axle tube (Inner side right before the diff) and that will stop you from gettting the axle all the way in.  You will need to "lift" the inner side of the axle with some type of leverage until it gets high enough to clear that bearing and slip "into" the pumpkin itself at which point you can line up the splines.  Also check that you are not binding up the U-joint on the spindle or knuckle any where.  Hope this helps.
-Funhog  

OK just thought about that, you are most likely doing the rear axle if it is a CJ5..ignore the part about the U-joint binding up and just try to pry the inner side of the axle up.

-Funhog