2320 Pto shaft is bogging down / slipping !!

mx125 · Oct 6, 2022

I seem to be thinking about it backwards. I guess the charge pump test port location on the hydrostatic plate is just an odd but convenient location.

And I have read manual many times along with schematics, theory of operation and searched parts diagrams. Nowhere is there a comportment location of “charge pump”. Nor parts for charge pump. The pump you refer to is the “hydraulic pump” …. And you are likely correct … but why is it defined completely separately to the “charge pump”. Manual outlines the hydraulic pump as solely for other use. And there is zero reference in diagram or any part with name of the priority control valve. Bizarrely unhelpful manual and definition.
Would have saved me two transaxle removals.
Hopefully dealer will attack the external pump and find a blockage or leak.

mx125 · Oct 9, 2022

While I await the dealer to call me, can you help me understand the missing components and flow? I seem to have misunderstood flow of process. If the hydraulic pump on side (with the pto senenoid attached) is actually also the “charge pump” how does it work? As the Schematic describes a charge pump and a differnt circuit for other uses, yet there is no “charge pump” in parts or component location. Are there effectively two “pumps” in that pump. One that feeds implements and 3 pt hitch, and one that feeds charge circuit and of course pto? And where is this “control valve“? No documentation on that. I get good advice on location of general tractor issues but Deere manual and parts does not answer the question.

Also, should I assume the entire sump is at 100 psi? Or just certain parts of housing. Would be nice to understand the real flow etc. There are no oil lines to the hydrostat or the plate with the charge pump test port…which is also confusing.

oldnslo · Oct 9, 2022

Mx
I agree the charge pump circuit is confusing. The schematic you posted shows two separate pumps but neither of us have found a second pump dedicated to charge circuit. I know the older Kubota BX used a single pump for all functions. That system had a priority flow control that supplied oil to steering, PTO, and charge. Your schematic did not show this type of system.

Wish I could be a little more helpful.

mx125 · Oct 9, 2022

I appreciate it. At least I don’t feel as dumb ! Surprised Deere does not have better service manual.

oldnslo · Oct 9, 2022

Agree on service manual but did Deere build this tractor or rebrand a Yanmar? My Branson service manual leaves a lot of information out.

mx125 · Oct 9, 2022

It seems the 2320 was made by Yanmar in Japan according to some other threads.

beenthere · Oct 9, 2022

Built in August, GA

dollarbill17 · Apr 30, 2023

mx125 said:
While I await the dealer to call me, can you help me understand the missing components and flow? I seem to have misunderstood flow of process. If the hydraulic pump on side (with the pto senenoid attached) is actually also the “charge pump” how does it work? As the Schematic describes a charge pump and a differnt circuit for other uses, yet there is no “charge pump” in parts or component location. Are there effectively two “pumps” in that pump. One that feeds implements and 3 pt hitch, and one that feeds charge circuit and of course pto? And where is this “control valve“? No documentation on that. I get good advice on location of general tractor issues but Deere manual and parts does not answer the question.

Also, should I assume the entire sump is at 100 psi? Or just certain parts of housing. Would be nice to understand the real flow etc. There are no oil lines to the hydrostat or the plate with the charge pump test port…which is also confusing.

What ended up being wrong with this? I'm having the same problem.

JCByrd24 · Sep 30, 2024

Can anyone provide an update or resolution to this thread? I have lost PTO in all PTO positions. I had a neighbor kid sitting on the seat and playing with the controls and through he must have knocked something into the wrong position, but I've now gone to the point of checking the PTO relay, voltage at the PTO solenoid coil, and magnetism and all of that is working but I have no PTO. Fluid level is good and clear and bright. I pulled the valve stem (that coil bolts to) and the spool inside moves freely and popped right out. I've called the dealer and they were no help, about to order the service manual but it sounds as though it leaves something to be desired. I see there is also a PTO relief valve in the circuit. Tractor mowed fine with no issues last time I used it.