I just did this service on Saturday. Overall, wasn't too bad. Some notes:
-For the most part, the video from Atlantic British is spot on and absolutely invaluable. Watch it, get all the bits ready in advance, it will save a lot of time. On mine, the heat shield and bracket under the pan was missing, they must have gotten rid of that thing in the LR4s(the vehicle in AB's video is an LR3). I cut the old neck off with a saw, didn't take too long.
-Almost 5L of fluid drained out, about the same amount went in. Not a huge fan of the way LR adapted this ZF transmission to fit in, the cross member and exhaust pipe get oil all over them. Oh well. Fluid used was Febi Bilstein with the LRN-13754 pn.
-I honestly liked to have used the old pan bolts again as they were beefy-looking T40s, rather than the relatively flimsy looking new allen bolts that were supplied. But, ended up using the new ones and torqued to 6 lb ft. Used permatex tack sealant on the gasket, no leaks so far, no issues.
-Truck had 76k on it. The old fluid looked OK, nothing terrible. Magnets had minimal shavings.
-I elected not to change the connector sleeve. Access looked particularly terrible and I was afraid to mess something up. It looked fine and I guess I can wait until/if it starts leaking. What are the symptoms when it does start to go?
The result is good. Shifts are super smooth(noticeably less rough), and the main difference I'm noticing so far is that when slowing down, it downshifts much more smoothly, whereas before it was much rougher and jerkier, especially when going 3->2 and 2->1
I also replaced all the diff fluids and the xfer case fluid. Went RP Synchromax in the xfer case and RP 75w90 for front and rear diffs. I have a rear locker.
Finally, I installed the dampener on the transfer case to quell the vibration/humming that was noticeable in a narrow rpm range(2500-3000rpm). There is a vacant hole in the transfer case housing. It appears unthreaded but I think it was threaded at one point and got oxidized over time, since there was nothing in there for so long. The re-threading was easy and now the vibrations/humming is gone.
One question: noticed that both driveshafts(front and rear) have a noticeable amount of play when turning them, along with some clicking. Is that normal? Driveline feels fine otherwise, when driving.
Overall, happy I did this. LCAs are next! Cheers!