I really have to admire your restraint. If I had purchased, what I believed to be, a first-rate lathe, and had the spindle and bearing issues, I would have either returned it, or insisted that they send a tech to make it right. I understand that with most Chinese machinery, it is to be expected that it's not a finished product and some work and/ or mods will be necessary. This was the case with my Grizzly G0602. It worked fine out of the box but I've done some work to make it smoother, more rigid, etc.
With a "South Bend" ( quotes intentional) I would expect that it was a finished product. I do understand that things can go wrong, but if the issue is a factory defect ( witness grease on the bearings) , the factory ( in this case Grizzly) has to make it right without the owner doing the repair.
Let's say we purchase a new automobile and there is a wheel bearing problem. I take it to the dealer and they repair it under warranty. They certainly don't ship me the replacement bearings and say "have at it."
You can't just drive the lathe to Grizzly if you are a thousand miles away and even if youre close, moving a lathe out of the shop, into a truck or onto a trailer is not a trivial task.
It seems that we are now expected, after spending thousands of dollars (or whatever you unit of currency happens to be) on a tool, to repair an in-warrenty problem. This is not acceptable.
I don't know what the solution is. Grizzly is not a small Mom and Pop distributor. They have major resources, but it appears that these resources are directed more toward sales than toward customer service.
While anytime I had an issue with my lathe, Grizzly was very good about sending parts, this is what we should expect. That's only a part of the solution.
Suppose you have never replaced a bearing or removed a spindle. I would be quite uncomfortable tearing down a new, multi- thousand dollar lathe.
Forgive the rant and rambling and I don't have an answer.
Just saying.