JD 570A Issues

[Recapirt]

Have had an old military surplus grader with everything worn out, used mostly for snow removal. They must have replaced the engine cause it runs great, Everything working fine then all of a sudden no drive like clutch slipping. Checked oil is ok, there does not appear to be a clutch linkage, clutch pedal cable goes to a valve body on the transmission any ideas where to start checking or is clutch out. Went from working fine to slipping instantly. Thanks

 

[AndrewC]

There is a transmission disconnect in the cab. I lost my 570A operators manual recently so I cant show you a picture. There also is a tow lever on the right side by the transmission. Check those first maybe some of the old timers can point a few more things.

 

[rsherril]

The 570 is a "hydraulic grader". The engine powers a pump which then runs the transmission and then the rear wheels. Putting the transmission in the "tow" position with the lever AndrewC was describing disengages the hydraulics from the transmission and could be a cause. The "clutch" you mentioned is a hydraulic device used for creeping but not for shifting or taking off, and shouldn't be the problem unless a broken hose is involved.

Start with checking the hydraulic oil level in the transmission with the dip stick for that purpose, (not sure if this is the dipstick you checked or if that was the engine oil dipstick). If it shows on the stick your problem is probably else where. If the forward reverse cable is disconnected from either end, the transmission might be in neutral with no way of engaging it from the cab. Check the transmission end to make sure that the cable is connected and moving with the direction selection lever. The speed selector lever also has a neutral position which can be checked there too. Of course the grader should not be running for any of these checks unless your are in the operators seat.

Worn out usually means neglected so if you decide that this is a machine you want to keep, it would probably be worth your time and money to have go through it with a knowledgeable mechanic and put money into oil and filter changes, both hydraulic and engine. Grease it all around and make sure all fittings are working. John Deere parts diagrams are available online. In my opinion these machines will hold their value if they are taken care of.

 

[Recapirt]

Thanks for the replies, I should add that the machine drives with no load, when trying to blade it just stops moving when the machine comes under load.

 

[excavator]

Just a bit of information. If you do end up having to go into the tranny, a 570A tranny is the same as those used in some of the same vintage ag tractors with power shift. I know it's the same as the 4020 but probably several other 20 series tractors also.

 

[Delmer]

If that's the case that this is a 8 speed forward, 4 reverese powershift transmission then here's your suggestions for transmission slippage starting with most likely and/or easiest to verify.

Low oil level

Restricted oil filter

Clutch pedal linkage adjustment

Weak/broken pressure regulating valve spring

Excessive clutch or brake element seal leakage

Filter bypass valve stuck open.

Transmission pump suction screen restricted

Low transmission pump flow due to worn pump or manifold gasket leakage

Pressure regulating valve housing gasket, shift valve housing gasket, or piston seal leakage.

Then there's other suggestions for unit will not move in any gear, with or without loading the engine.

Do you notice any difference in the gears and which do what? Is there a driveshaft that you can see to verify that the transmission is slipping when it stalls? Have you pulled the suction screen and/or filter to see what you find?

I believe this or similar transmissions are used in backhoes, skidders, etc? so it's not some oddball that nobody knows anything about.

 

[Showpony]

If your hydraulics are functioning at low engine idle with the transmission at operating temperature, it is most likely a worn torsional damper ie the clutch plate between the engine and transmission. Check you clutch pedal adjustment and ensure nothing has lodged behind or under the clutch valve arm on the side of the transmission.

 

[AndrewC]

I was told at one time the clutch was used to cold start/ inching and if it wasn't used it would seize causing the clutch to slip and then burn the clutch out.

 

[rsherril]

Here is what I've learned so far. The 570 A has a similar power unit as the JD 4020 series tractors. There are a lot of them around. Start with the simple stuff and good luck.

I'm working on a saddle pin unit for a 570 A and I could use some myself.

 

[AndrewC]

rsherril. I looked at your post. What else do you need to know? Looks like you have the service manual and you can buy all the seals through deere still. If its the new s/n it looks super simple. Just some orings.

 

[rsherril]

I think I've identified the problem and it is the piston ring seal, ( a metal ring). Shining a light behind the assembly while it is in the barrel revealed a pin hole between the piston seal and barrel. As I slide the assembly further back into the barrel, the gap disappears after about 1.5 inches. The parts manual doesn't specifically identify this part so I ordered a new piston to see if it is sold as a unit. To confuse matters further, the diagram in the parts manual really doesn't represent well what I have in my hands. The technical manual has a diagram that does, but it also has a couple of back up seals that ride on the pin beside the piston that I don't have. Because there is an older version of this cylinder I suspect that there were modifications made at the factory that didn't make the parts manual.

My understanding is that enough hydraulic oil is going through the pin hole to prevent the pin from retracting, but because the gap is closed when the pin is retracted, it has no problem reversing to the engaged position. My hope is that a new seal plus a cleaning of the pin bore will be enough. Worse case may involve a new cylinder barrel. For me, parts are several days to a week out. (The parts guy referred to my 570 A as a "mature grader", but the good thing is that there are a lot of them still out there working for people who need a reliable machine.)

 

[AndrewC]

Update your own post with this and we'll go from there

https://www.heavyequipmentforums.co...0A-Saddle-pins&p=506619&highlight=#post506619

 

[Recapirt]

Still working on finding the problem. Dealer says clutch parts are no longer available. Anyone know where to find parts, preferably new. If clutch is out, would be a good winter project if can get parts. Machine does what I need and will be impossible to replace if can not be fixed. Thanks for all the replies and help!

 

[Delmer]

Whoever said the parts are no longer available wasn't very interested finding them. I'll bet you can find the parts, but that's getting way ahead of yourself to start looking for parts.

I've never touched one of these graders so I'm guessing based on other deere habits. Do you know that you even have an operable clutch? sometimes deere called the clutch disk a "torsional damper" and it didn't operate, the transmission did all the "clutching". You might be able to take a look through the starter hole, and see if you can see any pieces. Otherwise it's time to get a pressure reading at the transmission, and maybe check the filter and screen.

 

[Trashman]

The 570A was a very popular grader for its time. You should not have a problem finding used parts for it on the web.

 

[rsherril]

I agree with Trashman's statement. I have found online and have had good results with a rebuilt engine from N. Dakota for another Deere product, (JD350). Had the local community college diesel engine program do the installation. You can also find after market products for older JD equipment too. Many people find them worthwhile to keep running as the cost for newer machinery is high and maintenance can be very technical and costly for machines that spend a lot of time parked. I suppose that it is possible to wear one out, but think that is mostly a lack of care and keeping up with small problems.

 

[Recapirt]

Finally took the time to tear into in the machine and found this wear in the valve body, the wear is the oil cooler relief valve. I don't know if this is causing the problem with not having 1 thru 4 and 7th gears. Anyone know where to find, PN R41404, Deere days no longer available and cannot find in any of their stores. Thanks

 

[Delmer]

"loss of 1st, 2nd, 3rd, 4th, and 7th forward" is caused by "C3 element failure, C3 circuit leakage, or broken sealing rings on reduction gear shaft". No ifs, ands or buts. You can do a transmission control pressure test, or look at this page until you understand it

http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt

The oil line (#17, 18, 19) is feeding oil to the C3 clutch and the oil is leaking somewhere along the line or at the clutch itself. #5A or 5B or #11 could cause your problem. A bad bearing would kill them. The shaft #9 is the transmission output shaft and should come out the rear of the transmission if there's a problem with any of those sealing rings.

I doubt the oil cooler relief has anything to do with the C3 clutch, but you could go through the transmission control test to see.