As for the synth oils. I would use Mobil 1 5w30 motor oil in the transmiaaion and transfer. It helps with cold weather shifts. Motor oil is the recommended. Other than that good old Dino works fine in these trucks. Make sure you adjust the valves every 20k or so. They can get too tight as opposed to loose. When that happens you can burn a valve, It was more common on the 2.3 than 2.6. Once you gone through everything just follow the schedule in the factory service manual.
KISS Principle = Keep It Simple Stupid.
Your best defense against Murphy's law!
We had one back home in AK. Served the family well. Did 6 trips on the Alaska Highway I finally replaced the engine with another that a friend brought up from the 48. That engine did The Highway 4 times and then I gave the Trooper to a teenaged son who beat the dog snot out of it. He finally threw a rod thru the pan and I gave it to a student that wanted a project.
If I could find another one of the old ones like your's I'd buy it and bring it to Juneau
Thanks to everyone! Now, what needs to be done to get this thing to sit level instead of the nose down look it has now? And are there better consoles out there? I kinda miss my broncos cup holders..
Sure, get yourself a 27mm socket and a long breaker bar. Jack up the front end to unload the suspension, and get underneath the middle of the Trooper and find the crossmember at the rearward end of the torsion bars. Spray some PB Blaster or similar on the large bolts there, and "crank" the 27mm bolts righty-tighty. The front suspension ride height will go up in the rough neighborhood of 1/4" per full turn of the adjustment bolt.
1995 Isuzu Trooper LS