Well might as well post an update. Its been 2 months of wrenching on it on my days off. From what I could find it was last overhauled in 08 from the markings on the diffs in marker and the widespread usage of the same red gasket sealant. I also found markings that it was an Army National Guard truck. For not having any formal vehicle mechanical skills, just self taught and youtube, it has been a learning and fun job. This thing is so rugged its hard to break. A 5 lb deadblow has been commonly used so far lol.
I've changed all the fluids except for transmission and coolant, but they will get it soon. I also went around and tightened all the hose clamps and other nuts bolts.
Portal Hubs had their fluid changed and I confirmed the spindle nut washer tabs that keep the nut from spinning off are locked on so that the tires don't go flying off. I need to replace 3 seals that are slowly seeping.
The 218 differential coolant line from the transmission (pulls heat out of the diff and into the transmission fluid) cracked (very common) resulting in pressurized transmission fluid filling the diff and the diff vent lines puking into the air filter (all items have vent lines that terminate in the air box). Since we don't plan on towing I bypassed this with hose.
Security:
Next was to install some sort of security feature since there are no "keys". My fab skills are not great but made a keyed battery cut off box that sits under the passenger seat at the passengers heels. The backside of the switch sits inside of the box and a small panel in the middle holds the switch. This is so that no one can "jump" the terminals. Then I installed a neutral cutoff switch. The truck won't start if it is not in neutral (a simple ball detent switch is activated when the shifter is in neutral) so I installed a keyed cut off in this circuit. Break the circuit and the truck doesn't start as it thinks it is out of neutral. This is the best "keyed" approach that doesn't risk cooking the engine control box. I hid it pretty good and blends in well. People have installed $15 keyed ignitions from tractor supply but they have a good chance of cooking a $1000 engine control box.
Battery Disconnect being mocked up.
Death Wobble:
Next was tackling the steering as it developed a hellacious violent death wobble at 35 mph. Enough to bounce us off the roof. After replacing an idler arm (jumped around) and everything else checked out as tight it turns out a tire went bad (I'm guessing the runflat). The search was on for a set of new(ish) tires. I found a guy selling a brand new set of 4 with rims but one rim had an old tire on it and I would have to change it. I didn't think it would be too bad, but man was I WRONG!!!!! I had already bought a HMMWV toolset off of ebay that had the runflat compressor. It took 7 hours to separate the rim halves and get the runflat out which is a 40ish pound doughnut of rubber. It took the compressor, another strap, sledges, wedges, and soap. Then another 3 hours to put it all back together. One note, is that Advance Auto will loan out tools for free minus a holding charge that you get back when you return it. I had to rent out a torque wrench to torque the 12 rim nuts (not lug nuts) to 125ft/lbs. Mine only went to 80 ft/lbs.
The batteries crapped out after a light was left on (thankfully not me) draining one battery to 7v and the other to 5v so I had to get new batteries. Since there are very little electronics on the truck ,I put in two 24F batteries vs the larger T6L forklift batteries and saving $250 as they just have to crank the truck.
The seat cushion foam had disintegrated so I bought some new heavy duty foam and hand sewed it into three seats. It is much more comfortable to sit in now... If there could be any comfort in these things.
Up next is fixing the horn and installing a license plate light to make it road legal. Other fixes will be to replace 3 seals on the portal hubs that are very slowly seeping, transmission fluid/flush, coolant flush, install an interior light and then remove the shims in the rear suspension that keep the tires vertical when loaded to the max. Then I'm hoping to build some half doors for the summer out of some aluminum sheet.