[benoit454]

One is you need special tools, like a dial indicator/run out guage to check backlash. You need to press the pinion bearing on and off as well as the carrier bearings if you change thoose. if the pattern isn't borrect you'll be taking off and putting on the bearing on the pinion many times.

Also the pinion gets a set preload and that crushes the sleeve. You can't uncrush it if you go too tight so you need like an inch lb torque wrench. Also the pinion nut is large like 1-1/4 so if you don't have that socket you need to buy one. As far as tear down that parts easy, but putting it back together isn't bad either, as long as you can set the preload correctly, then check backlash and pattern.