I just noticed a small puddle of gear lube on the driveway and upon
inspection found the right front axle shaft has popped out of the axle
tube by about 1/2 inch. I don't know ho far the truck was drive like
this but probably less than 50 to 100km. Questions:

What retains the axle in position (pressed on bearings)?
What is the likely damage (from those of you who have experience with this)?
What is involved in fixing this?

Tho' I'm not a Lic'd mechanic, I'm very experienced in Auto repair; just
haven't yet worked on these axles.

Thanks!