PARTS SEARCH >> EATON 851 Hydro-drive

[Rob47]

My Ferris Pro Cut 61 with Eaton series 851 hydrostatic >>> works but makes noise in forward, not reverse. It also struggles going up gradual grades.
My next move was to get internal pump parts in hopes of repairing a loss of pressure. After contacting Eaton I find that they quit supplying parts back in 2011. They gave their dealers a chance to buy out their inventory, that deal did not happen.

<<<<<<<<<<<<<SO >>>>>>>>>>>>​

I am now asking the world wide web if someone did choose to buy up parts for that relic hydro unit. And if they are wanting to sell some of them.


UPDATE; I don't know if anyone is watching this thread, but an update is needed. I have combined the parts of 2 units and made one that is working OK at this time. It will go up a decent incline while mowing. Additionally, I can report to those who still own one of these relics, under full load and full throttle the Hydro pump pressure has gone up to 750 psi. There is no specs for that but thought the community would like to know about it. 3/2/25

 

[BlazNT]

I would call these guys and see if they can rebuild it or have parts for it.
https://hydrostaticpumprepair.com/html/eaton_parts_eaton_hydrostatic_.html
(800) 361-0068

 

[Rob47]

I would call these guys and see if they can rebuild it or have parts for it.
https://hydrostaticpumprepair.com/html/eaton_parts_eaton_hydrostatic_.html
(800) 361-0068

I did contact them yesterday and they said no. I wrote again and they told me obsolete parts.

 

[eddychecker]

Have you solved your problem? If not, have you tried valve lapping compound between the pump gear and the plate and the pump gear and the output? Looking at your pictures, it looks like there are tiny gouges on each of those surfaces. Oil will leak past them and not drive the unit.

 

[Rob47]

I am not sure exactly where you are seeing the tiny gouges. Can you save one of my photos and draw an arrow to the area you see where there is a problem.
I have since put the unit back together and into the mower - I used it last week on an acre property. The noise is still the same going forward and not in reverse. It does drive the mower OK but I don't know what is expected from it in the way of speed as it would bought used. It has not seen any steep hills yet either.
Thanks for writing back.
I have also posted other remarks on this site;
[h=2]Ferris H2222K Hydro trans.[/h]

 

[eddychecker]

I am not sure exactly where you are seeing the tiny gouges. Can you save one of my photos and draw an arrow to the area you see where there is a problem.
I have since put the unit back together and into the mower - I used it last week on an acre property. The noise is still the same going forward and not in reverse. It does drive the mower OK but I don't know what is expected from it in the way of speed as it would bought used. It has not seen any steep hills yet either.
Thanks for writing back.
I have also posted other remarks on this site;
[h=2]Ferris H2222K Hydro trans.[/h]

I zoomed in on picture and put arrows where it looks like there are tiny gouges. If it's not perfectly smooth, oil pressure will leak and you'll have a loss of power. These machines whine, at least both of mine do. If it's just the noise you're worried about, don't. Here's the picture:

 

[Rob47]

I zoomed in on picture and put arrows where it looks like there are tiny gouges. If it's not perfectly smooth, oil pressure will leak and you'll have a loss of power. These machines whine, at least both of mine do. If it's just the noise you're worried about, don't. Here's the picture:

Thank you for your eyeball on this. I did look closely at these areas and my photo is not that good. The amount of scoring was minuscule - fingernail would not catch while sliding over it. I am also glad to know the noise is nothing to get alarmed about. I even took the planetary gear sets apart looking for something that was abnormal and did not find anything wrong there either. Still wonder why there is this whining noise that it makes.

 

[Rob47]

Ferris Guys, 7 years have gone by since I was posting here. In the meantime I found a new center section Hydro-trans and was able to shelf this old one. Now that new one has developed problems where it will hardly go up a slight incline - making a growling noise in the process and doing it slow. At this point I don't know if the pump rotor and ball assembly, or the drive rotor and ball assemblies are where the trouble lies - or all three. I found a guy on E-bay who can re-build this unit for $1900 -- I suspect he bores the holes larger in the rotor and then istalls larger balls to remove the alleged excess clearance. Regardless, it makes little sense to spend that kind of money on a rebuilt and not new unit when considering the whole mower (1996) may be worth $3000 on a good day. I am looking for parts, or a new unit --- or someone who has the skills to take it apart and fix it. I am already using 30wt. oil and a viscosity improver. Would appreciate any guidance !
See the above photos I have posted of the inside of the unit.

 

[Cyclon]

I also have 3 ferris pro 20s, this may sound ridiculous and you might have already checked this out but l had the same problem with one of mine, did you clean out the strainer in the Hyd tank? That strainer does get clogged with crap and the only way you know it is there is to see it in the parts manual. That will also cause your machine to bog down and no power and wine. But the Eaton transmissions do wear out and parts do not exist. Eaton did sell that type of transmission to other mowers, l think wheel horse and gravely, l think you might want to get a used one from someone or a mower grave yard. Mine need new gaskets witch l need to make myself, the pro 20s are great mowers and l have trusted them for years.

 

[Rob47]

I would call these guys and see if they can rebuild it or have parts for it.
https://hydrostaticpumprepair.com/html/eaton_parts_eaton_hydrostatic_.html
(800) 361-0068

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