I did my first set ever the past couple days and I would say I took about 4 hours to get it all done, I would bet it would take 2-3(maybe) if I were to do it again. This was one axle, and I am sure a pro could do it under 2.
install is pretty quick if you have the right tools but rember part of that time is taking everything off first so you can get the carier/pinion out 2hrs seems very quick.
install is pretty quick if you have the right tools but rember part of that time is taking everything off first so you can get the carier/pinion out 2hrs seems very quick.