When it rains it pours. I've got a 00 DII and my front drive shaft exploded about 3 months ago. It didn't get the tranny but the shaft is shot. Anyway, I pulled it and drove it without the shaft until I could get a new one ordered. Long story short. I drove it around 3 months. Lost my job right about the time that happened but I've found a new one a couple of weeks ago. I ordered a TW last week. BUT.........................Yesterday on the way home from fishing I went through a (looked like) a mud hole but it was basically just a big water puddle. When I got back out on the highway it started making a growling sound. I stopped and looked at it but didn't see anything major. It stopped making the noise the further I went EXCEPT when I go around turns and really get on the gas pedal. I'm stepping out on a limb here but I think it's my spider gears in the rear end. The roto looks fine. Anyone have any experience with this? What kind of job is it to replace the spider gears? I'm pretty mechanically inclined but would this be something for someone with experience to tackle or is it fairly straight forward? Money?

 

You very well could have killed your rear differential. It was not designed to take the full power like that for long periods.

 

Drain out the fluid in the rear diff and see if it looks funky. Any metal bits or shavings in it and it's destroyed. If the fluid's clear take a little flash light and shine it on the gears when you pull the fill plug.

 

If you have blown your spider gears, you won't be able to drive the truck.
As suggested, drain your rear diff and see if you have any metal chunks on your magnetic drain plug. In the mean time don't drive it.