Well, I will add some to this thread for the little it is probably worth.
My tractor is 2010 MX4700 HST. The position control valve is the 'type 3', part number YR908-00104. The 3pt hitch is jerky if I try to go from full down to full up in anything less than about 6 seconds. It is very difficult to get any movement less than an inch measured at the end of the arms.
Dealer got 'permission' from Kubota to take the top off the tranny and inspect the valve and adjust if necessary. In the dealers words, they found the poppet valve/set screw clearance way too wide and had to turn the set screw about 4.5 turns to get it into WSM specs. They then told me the hitch was smooth, but they were waiting on a gasket to be able to finish putting it all together. Since I had viewed this thread, I told them the first thing I would check would be for 'settling' when the engine was turned off or loader used when the 3pt was elevated. That was last week before I went on a short trip.
Today, I spoke to them again. They had checked for settling after my urging and found that to be the case as described by others earlier in this thread. They then tried backing off the set screw in 0.5 turn increments to get rid of the settling. The jerkiness returned by the time the settling stopped.
I was told the regional rep was in and had seen the tractor and was aware of my complaint. This rep had no immediate further suggestion for the dealer. Apparently, there is some 'big meeting' this week of regional service managers and he was going to ask around at this meeting for suggestions, fixes, etc....
The mechanic at the dealer told me the managers discussed putting in a valve from a 3010, but wanted to wait and see if anything materialized at the meeting mentioned above. I have looked at the parts blow ups of the latest
L3010 valve and the valve on my tractor. Although, they have different part numbers, they look identical to me. Unless there is actually a defect in my valve I don't think this valve change is an answer either.
So the tractor has been in the dealer's shop 13 days. When adjusted to WSM specs it is unusable due to the settling. (They agree I can't do serious loader work with 1200 lbs of ballast on the 3pt and have the 3pt jumping every time I move the loader.) They can get rid of the settling and return to jerkiness, but they admit it must be set outside of specs to even get that which doesn't seem right to them or me. Kubota was willing to pay for them to look into this initially, so Kubota didn't write this off as 'normal'. My dealer has three MXs on the lot. They all have jerky hitches to some extent, although I really think mine was/is worse. Of course the lot tractors all have one valve newer than mine (YR908-00105).
Encouraged that the dealer/rep still seem to be looking for a suitable resolution. Discouraged that I don't have a tractor that does what I need/think it should do.
Fortunately, we have not had and have no big snow in the forecast. It is too wet to do anything else, so, except the barn looking empty, I have not missed the tractor as of yet.
Wxman
Not that that has anything to do with this problem. But this dealership took an interest in my complaint and was willing to work with me to get it resolved if possible.