What's up guys, i'm fairly new to this forum as i just bought a 1970 Early Bronco. I was just wondering what type of fluid is needed for a Dana20 Transfer Case that is hooked up to a i think it's AODE/4R70W( The motor is supposed to be off a newer mustang. ) Should u be running ATF or Gear Oil The reason I ask is because before adding fluid to the transfer case the trans was shifting perfectly fine through the gears. We did a lot of work to the rig, new wiring harnes, thermostat( & housing ),etc. One week my pops checked the level on the TC and he noticed it was low so he added gear oil to the TC. Then when i took it out for a spin the trans wouldn't shift out of first. Any ideas why?