Ok, thanks, guys. I agree with both opinions. I guess it will boil down to price on that.
So, got rained out yesterday afternoon, which was probably good since it was 94 degrees out while I was working, but I really wanted to get inside that case. I just left it alone, cracked a couple of cold ones, and decided to hit it by 8 this morning.
I had loosened all of the T-40 bolts holding the halves together, so I finished pulling them this morning. Sticking a little pry bar between the ears on both halves easily split the case. I carefully pried a little all the way around with a large flathead to get an equal amount of space between the halves, so as to assist with making sure I pulled the halves apart evenly.
Here's what I was greeted with:
Ok, so no huge apparent issues like a destroyed clutch pack or anything like that. My first impression was, "dang, that pump filter is clean". I mean clean as in see-through. So, I inspect a little more closely:
Ok, so the tube on the pump is busted and the pump input is shoved up against the shift fork, tearing the pump input up in the process. This explains some of the fragments I found when draining the case. I find a little piece of metal sitting in the bottom of the case that is apparently a broken off piece of the pump - a flange that locks the pump in the correct position. Here it is at a better angle. Note the incorrect position of the pump. I also stuck the little piece of metal on top of the pump for clarification:
Alright, well, that kind of sucks, I think, and proceed to remove the pump. Well, great, the output shaft comes out with it:
It appears to be seized on there, and thinking about it, I suppose that would make sense if the pump's not doing its job.
Ok, so I next remove the helical cam assembly, shift fork, and hi low collar.
I'll be replacing the white plastic guides in the shift fork; only one of them is really beat up and the fork itself passes my visual inspection:
Hi lo collar is worn and should probably be replaced:
And that's where I'm at, specifically fighting with that dang snap ring under the planetary. Guess I need a better set of snap ring pliers, but we'll see. Good news is planetary turns nicely, but I figure I should pull and inspect, anyway.
The rest of the good news is that everything else in the case currently passes visual and tactile inspection, at least to me. Really, I'd imagine this thing's been serviced or rebuilt relatively recently, and someone did something really stupid during or after, while driving the vehicle.
Here's my assumptions/questions. Any negatives or affirmatives on these would be great.
[Edit: some answers to these I found after more research]
1. What would cause the tab on the pump to break? Is there something missing in the slot on the front case half allowing the pump to move too much? If not, I'm guessing a lack of fluid prevented the pump from doing its job and it seized up prior to the tab breaking.
Answer: Still don't know why it decided to break, could have broken before or after it seized. The pump tab does wear out the place where it sits in the edge of the case half. Can't go with Omega halves (which fix this) for now but Sonnax and Adapt-a-Case each make kits for this. I'm considering one of these kits a necessity.
2. That pump should just slide right off the output shaft
Answer: Yes, it was definitely seized.
3. Since the pump was not lubricating its connection on the shaft, it seized up
Answer: However it happened, yes, and definitely not good
4. If so, I may as well just try to beat the pump off of the shaft and hope for the best, since I'll probably need a new shaft.
Answer: yeah, tapped at it with a rubber mallet for a bit until it popped off. The softer metal from the pump seems to have melted onto the aluminum race, so I'm not so sure the aluminum underneath is unusable. I'll take a pic when I decide
5. Can't seem to find an output shaft or hi-low collar for sale. I imagine the collar is probably around 60 bucks or so, new, and that the output shaft is gonna be pushing $200 or so, new, if I can find it. Does this sound about right? Anyone know where to find the shaft? Are these shafts at all interchangeable between t/c's (like maybe from a t/c more easily available or cheaper)?
Answer: Found the output shaft, either with or without an included pump assembly from Motive Gear. Not sure how much, but a shaft for a 1354 can be hand for around $140 new. This shaft seems real similar to the shaft in the 4405, but no luck on finding out if they're interchangeable. Motive Gear has different part numbers for the 1354's. Anyone know if it's possible to use the main shaft from a 1354? Thought it would be easier to find one of these shafts. The hi-low collar can be found for $40 by searching for 1354-089-002 or by referring to it as a "range slider"
I'll probably have to rename this thread to "N00b Guide for Fixing a 4405 for cheap"

[/EDIT]
If anyone could help me out on any of these, it would be much appreciated. Sorry this was so long, and thanks for all of the help. I'd be screwed without it and the rebuild thread.
Bill