holeinmyhead0

I recently bought a 91 4 runner, and im trying to figure out if the rearend has been changed or modified. making it simple, the door jamb sticker says: g294 so it is an 8" rearend with 4.10 4 pinion open differential. If i am driving in a circle or doing a u turn in 2 wheel drive, it acts like an open differential, if i put it in 4 high or 4 low, it locks up the rearend and the inside tire spins faster than the ground under it. If i try to drive it somewhere a front and a rear tire drop, and dont touch the ground it spins the wheels not touching, and goes nowhere. any ideas, im new to 4wheeling myself but have knowledge in dragracing and such, so differentials are something i understand. From what i have read, it seems that i have a detroit truetrack, the characteristics seem to fit, but the seller said the car was purchased new by his aunt, and was stock. any help here would be appreciated, im going nuts to try to figure out what kind of diff it has. thanks guys.