So I had to take the trans and diff back to the yard I got them from. They tried to pass off flood car parts as good condition. It wasn't apparent until i had time to go over everything in detail. I scoped the diff through the speed sensor hole with my USB borescope. This is the ring gear:
The owner of the yard was tweaking or something and almost had my gun pulled on him. I showed him the pictures, video of the input shaft not spinning over, video of the borescope from inside the diff, and the rust colored fluid that came out of the transmission. It supposedly had 8k miles and no damage so it should have been cherry red and clear. When I told him he was acting like he was on coke his wife threatened to "Knock my god damn teeth out" because I had "Messed with the wrong bitch."
Mind you the guy came out there looking like he wanted to fight, wouldn't shake my hand, called me a liar, and an idiot. The place is a complete dump and it's run by a bunch of methed out trailer trash. He said they were going to take it back (no choice per their policy) but felt the need to continue to harass me. Once my refund had been issued and I had the receipt in my hands neither of them were anywhere to be found. I drove 6 hours round trip twice for that piece of shit.
The best part is he wanted me to bet that the next time he sold it that it wouldn't come back again. What a dishonest, worthless piece of shit.
My refund cleared today and I found a source for brand new stuff through a dealer at wholesale cost. It will be within $200 of what I paid on the used shit. I hope they both die of something slow and painful. I contemplated filing a police report against the woman but didn't feel like wasting any more of my time on them.