Yes check out the link someone posted above

 

Pretty sure you're right as it was a convenience compared to getting out and locking the hubs.

 

Here is two pictures of what I'm trying to explain to ya. The bushing itself is kinda hard to get to. So greasing the axle is what I always do and it works. My finger is pointing to the part that I always gob the grease on.
Your axle looks like this one. Grease were that flat washer/dust shield thingy is next the shaft that goes through the spindle.

This is basically the same thing just without the dust shield
it's a Fj80 birfield tho. I just replaced it about 2 weeks ago lol. That's why i still have this one

 

Ok guys well i greased it all up and the noise quit. Thanks alot for all the help but now i have another issue. So im thinking i put too much grease in there because i cant get the shaft out far enough to put the snap ring back in. so what i did was just remove that washer and put the snap ring in to get me home. Do yall have any tricks to pull on that shaft some how. And will it hurt anything for driving it with out that washer.

 

Screw a bolt into the center of the axle, and grab a hold of it while getting it back together.