Kubota 5040 had ball bearings in the hydraulic filter

Hello everyone I am new to this forum but have experience in others. Thanks in advance for any ideas, thoughts or help you may provide me.

I have a Kubota 5040 which is about 6 years old now. We use it on our golf course as our main tractor so it gets used a lot in pulling grooming mowers and pulling a big trailer to haul sand and cut up trees around the course. It has been a horse for us but about two years ago it started making a whinning noise which is pretty loud now. We think an operator let the hyd oil get low due to a leak from one of the rear quick connectors. We changed the hyd oil out replacing it with the UDT that Kubota recommends. when we pulled the filters we noticed ball bearings inside of it. I have looked through a parts manual at the system and tried to determine where they could of came from. I do not see a sump or a pump which would have a filter on it (like an engine) or a way for the bearings to enter the system. We know it could not of came from the hyd pump above the filters because there is no clearence for a bearing to move through it. I have to wonder if the bearings and the whinning noise are from the same issue. Other then the noise the tractor runs great.

Do any of you have any idea of where the gearings may have migrated from? or how about what may be causing the whinning noise?

Any ideas will be checked out. While I do not want to split the tractor I will if it comes to that. It will be the first time with me splitting a kubota but I have lots of experience in John deers.

They were bigger then the quick connect bearings which are all still intact. they were not magnetic as they rolled around the filter when we were looking at them.

I went by my local Kubota dealer this afternoon and ask them about it. One of the guys had said he had seen something like this in a different tractor where there were bearings in the hyd filter. he said it was from the PTO. Our PTO operates ok and we have been using it all summer with no issues. The tech said they may have been picked up off of the sump but I questioned how it would get there when the parts manual does not show a sump pick up tube. they looked into their manual and saw the same thing as I did.

One other option would be the hyd pump located right over the filters. It has small bearing size check valves (I think thats what they would be). I would think that if these got out the pump would not work.

We have been using the tractor for half a year since finding them. No problems yet! With this being our slow season I had figured to try to find the issue and fix it instead of waiting for the whole tractor to seize up.

The only issue we have with the tractor is the loud whining noise when it is running. It whines all of the time, with the PTO on and without it! I think some of the wet clutches got run a little to dry once and is causing it to whine. Any thoughts on this would also be welcomed! And thanks for your input. I look forward to also helping other down the road. I have been working on Tractors and other golf course equipment for 30 years. It just gets in my craw when something does not make sense.

It still whines when the clutch is pressed. The only time it does not whine is when idle and even then you can slightly hear it. as soon as you step on the gas it gets louder.