I love it. i only have a few miles on it so far. I will be going on a trip and will post any mpg increases. Turning in 4 wheel drive is bump stop to bump stop with no torque binding. Driving, turning, and 4 wheel drive is much smoother. The seal is installed in the cad location. I removed the bushing and old seal and installed the new seal where the old seal came out. There is no place for the seal at the diff. The diameter on the new shaft for the seal is . 020" of an inch smaller than the new shaft dia. The shaft is smooth enough to accept the seal at the cad location. No leaks and it will work as if it were made to go there. I have lots of experience in machanics, including school, and machinery . I'm stating this so you know that I know what I'm doing. I reinstalled the cad vacuum motor and housing so all hoses would hook up and I would not have to plug them. No problems with the install. All went together perfectly. Very pleased. I'll update when I can. Bunyan