Houndstooth, FYI, I have requested the service report for whatever they did to my tractor, but evidently the service mgr is on an extended vacation. I've used the tractor 2-3 times per week since getting it back from the dealer. So far, the loud grinding and the lift system groan have not happened. This morning, I did notice a jingling sound on the right hand side, near the HST pedals, that was evident when the bad noises were occurring. Previously, when the jingling occurred the lift system would groan loudly, vibrate severely, and operate very slowly. Those things didn't happen today, so I'm pretty happy about that! I'm still nervous about the bad noises recurring.
The noise I've heard and complained about, and hopefully has been fixed, is no where related to the normal hydraulic moan/whine that some folks complain about. To me, that moan/whine is sweet music, it means I have HST, and all's well. The grinding noise I heard was nothing like the normal moan. It would drown the normal moan out, but was intermittent, and hard to predict.
I want the service report so I can give you a clue as to what they did, officially, other than remove the pump, change a bunch of o-rings and seals, and change to the lower temperature hydraulic fluid. Maybe those in-the-know will recognize the actions they took and confirm that whatever they did would definitely cause a problem like I had, or help in the diagnosis of other folk's problems.
If your tractor is making a noise like your pulling a grader blade down a paved road, beleive me, it's not normal. Now what to do about, gets detailed and involves using a video camera and jumping though a whole lot of hoops. I hope you don't have those problems. I'll post the summary of the service report when I get it. At the same time, I'll give details of an issue I'm having with obtaining a work light, if that continues the way it's headed. You won't believe it, but for now I'm holding my tongue. I'm waiting to see how things have proceeded since Thursday. Good luck on your noise issue.