I will soon be replacing the engine in my 2001. At that time, it makes sense to me to either rebuild or replace the Allison attached to it, since it will have nearly 200K miles. The transfer case will also be replaced or rebuilt at this time, as it has the classic leak and the same miles - many in 4HI plowing snow in a repeative, backward and forward manner.

Any experiences with cost and effectiveness of simple rebuilds vs. replacements appreciated. I have seen rebuild kits for sale, but wonder if this really addresses all the internal wear points?