2000 Ram 1500 Transfer Case

When I was leaving work for the weekend, I put the truck in reverse, it moved about 10 feet and THUNK - the engine was still running fine but no movement. I had no action in any forward or reverse gears and there was a light grinding noise when I put it into park. I coasted back into the stall. I had to set the e-brake because even in park the truck would roll. I checked to see if my tranny had fallen off (it was still there), checked fluids (everything fine). I then crawled underneath to find a huge crack in my transfer case.
Now the questions - what transfer case do I get and is it a huge ordeal to swap it out myself? The manual and the dealership say it should be a 231HD. All shops and websites I've found say it's a 231D. One shop said it would be 2 hours labor, another 4 1/2 hours.
HELP

You need to determine it by your engine and tranny sales codes. there may be a part number on it also.
Were you planning on swapping in a rebuilt or a used one?

if your mechanically inclined and have some tools pulling out a Tcase is not a bad deal. Front & rear drive shafts, breather, Vac lines at switch and shift linkage & possibly the trans mount and bracket. It should tell you on the round tag by the fill plug on the Tcase it should say 231 D or 231 HD at the top. The one bolt on the top a mid depth socket and a universal joint helps alot. you should also check all the ujoints to see if one is bad. When ujoints go bad then can and will bust a cases

The case says 231D - went with that - it's working great now. Thanks!