Ford Differential

I would get a second opinion.. rear axles rarely go bad... Once I took my 3 year old truck to the local dealership for a state inspection.. The shop manager came out and told me the differential was bad in my truck and needed repaired.. As a former inspection mechanic, knowing that the differential is not an inspection item in my state and having my license for over thirty years I pulled out my cell phone and asked him not to do anymore to it as I was calling the state police barracks down the road and ask them to send the state police inspection mechanic to come look at it... He said he was going to check with the mechanic working on it and make shure it is bad... A half hour later my truck was ready with a new sticker and nothing was said about the rearend...