Working my winter project, doing the inside of the cab, and I want to pop the top off of my tranny for a visual. Looks pretty straight forward and simple.
Clean it off good, put shifter in neutral, pull 8 bolts, lift off and throw away gasket. Good visual and magnet check.
Reassembly is making sure forks go in proper place.
Any tricks I need to be aware of or critical areas to inspect?
From doing it a while back, there was no trick to it, it was straight forward like you expected it to be. It wasn't hard to get all the shift forks to line up for reassembly.
As far as things to inspect, check all the gears for chipped teeth, and be aware that the rounded edges of the unsynchronized first and reverse gears may have some minor chips from not waiting until things stop spinning before trying to engage them. The one in my truck, my spare, and my parts unit all do. Not a big deal as long as the damage is small.
Check the teeth on the engagement collars for the synchros to make sure they aren't heavily worn. If you have a gear that is hard to mesh, that could be the culprit - #4 had half the teeth worn off on mine. This may involve needing to push the shift collars forward or back, just return them to center before reassembly. Make sure there isn't any slop between the input shaft and the main shaft where the roller bearings go - any looseness there could indicate a problem with those rollers. Check to make sure that the gears that spin on the main shaft don't have too much play. Check that the bearings spin smoothly without slop on everything when you have the transfer case in neutral and the clutch pressed in.
Make sure the pads on the shift forks aren't bent or worn too badly. Make sure all the set screws holding the shift fork parts are still safety wired. If all that checks out, short of measuring anything for wear / tolerances or taking it further apart, it should be good to put back together with a new gasket and rock on.
If you do find a worn out synchro or something wrong with the main shaft or components on it, that can all be done without removing the transmission from the truck, you just have to remove the jack shaft to the transfer case and the associated seal housing and output shaft bearing. I replaced that synchro in an afternoon and had it buttoned up the same day.