I've been busy and have pulled the engine/trans, found the trans issue, and am already addressing other found issues. The problem with the trans is a broken fifth/reverse hub like I had suspected. I've had hubs sick and/or seize completely but never break apart.
While everything is out and easily accessable, I want to replace anything questionable that I haven't already changed. Things like the flexible clutch hose, turbo drain hose (elbow to the oil pan), and transmission cooler lines. I visited a local hydraulics business yesterday and brought all these items with me but unfortunately, it was either a machine was broke or they didn't have the materials. . No worries, I stopped by Toyota on the way home and was still able to order the turbo drain. The clutch hose is unfortunate because I was hoping to have them make a braided one but no worries, I'll order a standard one from rock auto.
As for the trans cooler lines, as much as I wanted them to do the work, I figured I could do an ok job. I didn't want to gamble putting theses back on without trying so I picked up some power steering hose from the parts store and disassembled and replaced every soft hose. I'm glad I did too because after cleaning and removing rust from all the steel tubes, I found two pinholes in one barbed fitting that was apparently holding water between the hose/fitting. All that's left with these is a coat of paint and they'll be ready. . . Well, after I flush the cooler to get all the flakes out of it.
Other things I've addressed are the hose from hell, the distributor leaking, and the removal of all TVIS components since I found that the diaphragm was shot, I'll be ordering a phenolic intake spacer soon. The distributor was leaking past the internal shaft seal and since these distributors are not easily replaceable, I decided to rebuild mine. Twos R Us sells a rebuild kit, I've already received and installed it. . crossing fingers that I did it correctly.
The transmission will be for parts only, I will not be rebuilding it unless absolutely necessary. I am getting two transmissions from Andy on here and will make that 17 hour round-trip drive at the end of the week. I'm getting both of his spares because I figured with as far as I'll be driving, if something is wrong with one, I'd rather have a backup than make that trip again. Worse case, if both are bad, surely I can make a good one from the three.