I was out running my truck earlier and a rock got wedged under the 4WD shaftbehind the engine (I'm tired and can't think of what its called). I didn't realize it a first until I noticed that the right rear wheel wasn't going when I hit the throttle. About 3-4 minutes later, the left rear wheel stopped going as well. Now that its off, the left rear will spin about 1 full revolution and then lock up. The right rear spins freely without stopping. I want to take it apart tomorrow, but I don't have a lot of time so I want to make sure I am looking at the correct thing. It's the rear differential, right? And just so I can sleep tonight , is it most likely just one of the small gears inside got strippedor could I be looking at replacing the entire diff? The XL diff seems kinda pricey. Thanks!

-Edit- It is definitely not the dogbones, they are still intact.</p>

Sounds like you damaged the spider gears inside the diff assembly. The only way to verify the problem is to disassemble it and take a look.

I took it apart and the gear that is attached to the drive cup (I believe its called the pinion) was broken in half. The rest of the gears appear to be fine. However, the pin that holds that gear to the pinion was missing and is nowhere to be found. Weird.