I'm gonig to make a guess here... You seem to have good mechanics and good parts. So I'm thinking you either have it in 4X4 and hit some hard packed soil which will BIND up the drive train. OR you have at least one tire that is out if size with the others.
4X4 is intended for loose soil only. Using it on hard packed soil or pavement will result in loud pops.. caused by the different speeds of the wheels. This is a NORMAL happening occuring with almost any 4x4.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist