John Deere 500C Transmission/Hydraulics Problems

[Stephent_16]

First Post,

I recently acquired a John Deere 500C that starts and runs well. All of the hydraulics are functional but they are weak. As for the transmission, 1-4 in forward will not move the machine. You can feel it shift into these gears but the machine does not attempt to move. Gears 5-8 are functional and seem like nothing is wrong with them. In reverse, 1 and 2 operate as normal but when shifted into 3-4 it bogs the machine down and stops it from moving.

The hydraulics all work but they are not strong. There is the occasional chattering in the hydraulics when lifting the loader up and down. I am not 100% sure where the suction screen is but the previous owner removed the two hydraulic filters and did not replace them on the machine.

I was planning on draining the oil to put hydraulics filters in it and pull the screen out to see what it looks like. Where is the suction screen located and what steps would you recommend me taking to resolve these issues?

 

[JDfan500C]

I'd start by trying to find a parts manual on the break down of the machine. I have one and will check later.

 

[Tinkerer]

Here is an example of your parts book. In the LH column expand the letter of the name of the part you are looking for.
http://jdpc.deere.com/jdpc/servlet/...?wvsessionid=cd61738c15014d68a479d510a2188599

 

[Delmer]

Are you sure 7 works? Failure of 1-4 +7 forward indicates the c3 clutch is not engaging. There is no clutch lock up that will explain 3+4 reverse locking up with the others working, possibly internal valve leakage (lucky for you possibly).

This is from the service manual for a different backhoe with the 8F 4R powershift transmission. I'd suggest buying the service manual "Operation and Test Technical Manual" for your model. A filter and clean screen will not fix the trans.

 

[Stephent_16]

Are you sure 7 works? Failure of 1-4 +7 forward indicates the c3 clutch is not engaging. There is no clutch lock up that will explain 3+4 reverse locking up with the others working, possibly internal valve leakage (lucky for you possibly).

This is from the service manual for a different backhoe with the 8F 4R powershift transmission. I'd suggest buying the service manual "Operation and Test Technical Manual" for your model. A filter and clean screen will not fix the trans.

I am not sure about +7 forward but I will check that out. I will also look into getting service manual.

 

[Tinkerer]

Here is an example of your parts book. In the LH column expand the letter of the name of the part you are looking for.
http://jdpc.deere.com/jdpc/servlet/...?wvsessionid=cd61738c15014d68a479d510a2188599

I see the link I posted times out after a while and the link just brings up the model search. But, type 500C in the search box and everything is there.

 

[Stephent_16]

I see the link I posted times out after a while and the link just brings up the model search. But, type 500C in the search box and everything is there.

Yes, I was able to find the breakdown of the filters and where the screen is located. Looking at the picture, it looks to me that the screen is under the filters. There is a plug is this location but it also has another line going into it (attaching to #24 in the picture), which is not shown in this picture.

 

[Stephent_16]

Update:
I drained all the fluid replace the filters (turns out it did have filters) and clean the suction screen that was pretty clogged up with clutch material. While draining the fluid, pieces of what seems to be clutch components were flowing out in the oil so I think the transmission need to be redone.

Delmer:
As you had mentioned, 7+ is not working as well

 

[Stephent_16]

Does anyone have any recommendations for what my next steps should be? The machine acts like it wants to shift into those missing gears. I think it definitely has something to do the the c3 clutch but I just want to exhaust all options before I split the machine.

If you leave the machine in gear while trying to use the loader the hydraulics will die out and sometimes the hydraulics will rattle like it has air in the system.

Any thoughts would be greatly appreciated.

 

[omansnowy]

Does anyone have any recommendations for what my next steps should be? The machine acts like it wants to shift into those missing gears. I think it definitely has something to do the the c3 clutch but I just want to exhaust all options before I split the machine.

If you leave the machine in gear while trying to use the loader the hydraulics will die out and sometimes the hydraulics will rattle like it has air in the system.

Any thoughts would be greatly appreciated.

Have you been able to resolve the issue? I have a 500B with a powershift 8F 4R that doesnt want to shift into reverse and some of the forward gears.
Thanks,
Oliver

 

[Delmer]

Which gears? get the technical manual and go through the testing process...

 

[omansnowy]

Which gears? get the technical manual and go through the testing process...[/QUOTE

Forward gears 1 and 2, all 4 reverse gears don't work. I will get a 300psi gauge tomorrow to start testing. Does anybody know the size of the fitting off hand? I don't want to remove the plugs before I have a hose to quickly replace.

Thanks

 

[Delmer]

1f, 2f, 7f, 8f, 1r, 2r engage C1.
C2 is disengaged in 1 and 2, both in both f and r. That's the most common link between the gears you listed.

your gears not working don't make sense to me, I'm looking at a manual for a different deere backhoe powershift though. i don't think they changed much, if you want to search info, "john deere 8 speed powershift" will bring up way more results than "500 backhoe", most of the problems will be similar regardless of whether the transmission is in a skidder, tractor or backhoe.


The common test port seems to be:
3/8" x24 M ORB
again, that's for a newer backhoe, might have changed?

 

[omansnowy]

It's a 500 series B .I know that B3 according to the TM1024 manual controls all reverse gears. What's an I looking for with the gauge test? An I looking to see if 160psi is read when that particular greais engaged, or am I looking for a drop in pressure?

 

[Delmer]

Yes, B3 is activated in all reverse gears. If B3 and C1 were not operating, then you would have 7f and 8f not operating in addition to 1f, 2f and all reverse.

There's a whole drawn out procedure to test the transmission, testing different leakages, blocking different valves, observing the pressure rise for different modulators..................

If you don't have 7f and 8f in addition to your other gears, then I can safely guess that you won't get pressure in the test ports to B3 and C1 because the oil is leaking out somewhere (only way I can think of for it to hold pressure and not work is if the internal splines on the plates are stripped off/shaft is stripped off). That's why the go through the leakage tests, if you have no pressure, the next step is to find where it's leaking, and the easiest way to do that is NOT EASY.

Back up a second, have you inspected the screen and filter to see what kind of debris you have in there? How's the oil level and other hydraulic functions? The newer manual that I have is good for going through the basic diagnosis steps, follow the basic stuff as much as you can. When you get to the seven gauge tests, you'll probably take a few guesses, but you still want to try to test a few things before tearing into it.

 

[omansnowy]

I have not checked the sump screen, I know that's the first step but both filters have been changed and ~11.5 gallons of fresh oil have been put in. The other hydraulics are a but sluggish buy I don't know how "quick" there's supposed to be. I have not owned this machine for long, and I normally operate much better ones. My thought is that if gears f3-6 are fine, then then the sump it probably good but I'll have to drain fluid and check again. Let me remind you that machine was flat towed 3 miles, lowspeed, engine off not in tow mode... At some point, back wheels both locked up and stopped the tow truck in it's Tracks. Only way to unlock the wheels was to turn on engine and let whatever food was in there too cool down. It was towed 200 yards more after that no problem but then lost all driving ability until fluid was refilled. Stupid... I know but that's life .

Thanks again

 

[Delmer]

I'm not thinking cleaning the screen will fix your transmission, more like the parts will tell what fell apart. You'll find chunks of friction material most likely. Maybe steel chunks? rubber?

I'm still curious if 7f and 8f work? I'd still try some of the pressure tests, and at some point pull the screen and then you'll see enough parts to pull the transmission apart.

 

[omansnowy]

I agree about the screen. There were done metal flakes stuck in the filters, nothing large. My thought is that one of the shift valves heated up from lack of oil and seized preventing reverse from engaging . How hard is it to remove the shift valve and rebuild it?

 

[Delmer]

A lot easier than taking apart the transmission. You can always dream.

If you still have the filters, cut out a square/rectangular section of the pleats, stick it in a vice, squeeze the oil out and then look into the pleats to see what is there. You'll see more without the extra oil.