Originally Posted by BlackWorksInc

The only thing I'd really add is that the FJ T-Case doesn't have the T3 Torsen center diff in it like the 4th gen units IIRC, so you might get a bit more binding out of the front end. The ADD (and the addition of the T3 Torsen in some of Toyota's T-Cases) was meant to reduce the binding you'd experience in 2WD and 4WD modes.

But honestly, if you've driven an FJ or a 5th gen non-limited 4Runner in 4Hi then you'll get a good idea of how it drives.

As for the leaking transfer case actuator, it's a bit of a hassle to replace (did I ever document rebuilding my transfer case? I can't remember it's been years :S ); but they usually don't leak that badly. The large majority of 4WD issues I see are in the following order; lack of regular use (seriously guys just run it through 4WD once every month or two for about a 100ft or so, saves so much trouble...), failed/failing position/detent switches, dipshits managing to lock up their transfer case in 4Lo doing dumb shit.

Interesting swap, I've thought about throwing the GX470 T-Case in my V8 for the fun shift lever; but sorta decided my money was better spent else where.

Post Note-

I will point out that the older 4WD systems are rather simple and don't have that many inputs/outputs to the rest of the vehicle, but the ABS system may not be super thrilled with you when you're playing with it in 4Hi/4Lo in certain terrains (mainly because the switch outputs do feed into the ABS to sort of "detune" the aggressiveness of the ABS/VSC/TRAC functions; though in my personal experience it'll still fight you off-roading in some cases. So wire up a kill switch to "disable" the ABS/TRAC/VSC systems, the easiest way is to hijack the signal from a wheel speed sensor (the driver's rear wheel goes through the junction connectors at the driver's kick panel" and just hook it to a switch. When you kill a speed sensor it'll throw the system into a deep failure mode and shut down a lot of it's functions (I had mixed luck with unplugging the master cylinder sensor on my own rig when the system was fighting me, I know it works for some people, your mileage may vary and all that.)

One more note, the majority of the reason the electronic units start to shift slow/stick has more to do from lack of regular use; the grease that lubricates the gears starts to clump around the teeth; it's basically a lot of gear reductions to get the shafts to move. Lack of use lets the grease thicken around the teeth (even worse during cold weather, 90% of the 4WD issues I see are because the system was never used since the previous winter and now that it's snowing outside they can't get it to move and the grease is gunky and thick) and the motor struggles to get the gears going. Hence why I mentioned you should exercise the 4WD and Center Diff lock somewhat regularly. You'd be surprised how many times I've used a deadblow to "unstick" the actuator and then just cycled it a dozen or so times and she shifts like brand new. lol