Someone mentioned just taking out the lock to make it an open rear end. Can I just replace the gear inside that actually broke? I'm sure somebody sells a kit for it.

 

I wouldn't bother with that. You shouldn't just install 1 spider gear anyway. You need replace all 4, since they are now worn as a set. Also, there's no way I'd want a peg legger rear end. Get a good used G80 and call it a day.

 

Found a used g80 out of an 08 with less than 40,000 miles on it on craigslist. The guy bought it from some old man and immediately upgraded to an eaton. Would the 08 g80 be the same as my 2004?

 

Yes, same unit. At one point, the clutches were upgraded, but can't remember the year. It will bolt up, as long as it is for an 8.5" 10 bolt, and not a 14.