my front axle has a grinding sound, its at a very low speed about 5 mph but after that its fine, any ideas to what it could be?

Check the unit bearing hubs.

I have a similar issue, only makes intermittent 'grumbling' sound when I turn left, seems to be only at low speed, and generally goes away after I drive it for a little bit (about a mile, like it needs to warm up) I have replaced both of the unit bearing hubs, and when I changed the diff fluid I didn't see any obvious issues (such as metal in the gear oil). Only thing I haven't done is changed the universal joint in the passenger side shaft. Hope this helps you in any way.

On another note, anyone have an idea how hard it is to re-bearing the inner part of one of these axles yourself?

Remove the front drive shaft and drive it. May be a d/s problem

X2 try this!