What gears?

If its not a sure grip(posi), you will have to turn both wheels at the same time, couse if your turning one wheel the spider gears will multiply the gear ratio by 2. Thats why if you do a lot on one wheel burn outs, the open diff is spinning the wheel at twice the speedometer speed. exp. Burn out and speedo says 50 mph the one wheel is going at 100mph.