Just picked up a 2001 Suburban 4x4 with 96k on the clock. It's cherry and we love it.

Being new to me, I'd like to start off with all new fluids. I'm a huge proponent of synthetic fluids and plan on using Mobil 1 for all of it.

What weight do I use for the

Rear diff
Front diff
Transfer case

I've replaced gear oil before but never tranny fluid. I assume there is a drain hole. Or do I pull the pan? Since there is dino oil in there now, how do I assure a complete drain including torque converter? I'd like to do a 100% tranny fluid change but is this recommended? I've heard that when you go into a shop to get a change you only really get a small % actually changed.

Any help would be greatly appreciated.