what we call the 'carrier', the service manual calls the 'case'. this is the part of which there are three series'. this is the part that the ring gear bolts to.
what we call the 'housing', or 'case', the service manual calls the 'carrier'. this is the outside cast iron part the axle tubes go in, and everything else fits inside. it is a 1 size fits all.
in other words, the service manual vs. most of the rest of the world use opposite terminology. if you try to go by the book, you will be told you are wrong, and everyone will be confused. feelings will be hurt, and children go to bed hungry.
in other words, in most of the real world, the case encases the carrier, or the housing houses the carrier, and in the manual, the carrier carries the case. confused? i am.