That's what I was afraid of.
Maybe it just needs new bearings? You will have to take it apart though to find out. I know some of these rebuilders will weld up and re-machine the shaft if it's damaged or worn.
Its funny that I couldn't even sell a used box because everyone is afraid of them. But some of the companies charge $250 for a core if yours is damaged or not returned just because of how hard the good parts are to find. To the best of my knowledge, the new OE boxes stop being produced around 2010 or 2011 from what I read. Everything else is China.
Even some of the NEW boxes are just high quality reman boxes. They completely go through them with a blast and a chemical bath. Then they seem to pchemical coat the housing or a high quality bake on paint, then assemble with a new parts kit and adjust to spec. But the housing and the sector shaft are often reused as long as they are in spec with no damage.
All blue top and red tops are is basically the same thing. They are a high quality rebuilder so you pay for the attention to detail. In some cases they improve upon the weakness of the OE design.
They are alot more strict on what gets re used and what gets replaced.