5020 throttle linkage and injection pump

luckyfarmer

New User
Hi all. I tried linking this message to an older post but it does not seem to show up so I thought I would retry.

Recently, I replaced the steering valve on my 1967 JD 5020 as it was leaking a lot. While it was out, I decided to rebuild the throttle mechanism and replaced components that had significant slack in them. I then went on to adjust the mechanism (according to the service manual) but noticed that there was a lot of play on the linkage on the injection pump, i.e.: the handle on the side of the pump has to move quite a bit (without significant change in RPMs) between low idle and shut off. As a result, I am unable to adjust the entire mechanism so that the tractor can be put at high RPMs and also be allowed to be shut off with the handle throttle.

The first question is: is this a problem with the lever on the side of the injection pump? If so, can it be adjusted? Is the problem somewhere else within the throttle mechanism. I have not had any problems with the pump and do not want to spend a $1000 on a new one. Please help. Thank you.
 
Did it reach both high idle and shutoff before the steering repair work? If so I'd think it's still throttle linkage travel somewhere. Pumps that use the throttle lever to shut down all have a dead range between low idle and stop position. This can be shortened some by shims inside the pump if needed, best done on a test stand.
 
Thank you for your response.

I have owned the tractor for over a year now and it always had this issue. You can either adjust the mechanism so that the tractor can operate within the high RPM range and not be able to shut it off with the hand lever or adjust it so that you can shut it off but get only to the beginning of the high RPM range. I had replaced the parts which were worn and have very little slack in the system at this time, I think. The
"dead range" on the pump lever is more than half of the entire working range - I am definitely losing a lot of hand throttle movement there. Is this amount normal? What do you think I should do?
 
I need to check the pump parts list and see what spacers, if any are used inside the pump. I've re-shimmed some before to lessen the dead travel on some IH tractors that shut off the same way. Last early 4020 I had in needed some linkage repair under the dash for the same issue. Remember moving a ball joint down some in a slotted arm to get more travel on it too. That helped the most on that tractor.
 
Thank you again. If I am reading you correctly, you feel the issue is not the injection pump?

I was reviewing the throttle mechanism again and it came to me that there is still play between the hub (#3) and the speed control tube(#11) as the U shape cut-outs in the tube are over-sized. Could this contribute to the difficulty in getting the operating range when the knob is in the "in-position"? This would potentially be a much cheaper fix. Thanks again.
a247777.jpg
 
Thank you again. If I am reading you correctly, you feel the issue is not the injection pump?

I was reviewing the throttle mechanism again and it came to me that there is still play between the hub (#3) and the speed control tube(#11) as the U shape cut-outs in the tube are over-sized. Could this contribute to the difficulty in getting the operating range when the knob is in the "in-position"? This would potentially be a much cheaper fix. Thanks again.
a247779.jpg
 
I'd correct the play you found first, have a hunch that will fix your trouble. When the pump needs serviced the dead zone could be lessened some at that time if needed. Have done several IH and Ford pumps on the stand to get rid of some play, but there will always be a little at the pump with the throttle lever shutdown.
 
Sounds like you are missing some parts. Shut-off is done by a little clip with an ear that clamp on to the throttle shaft and I assume you have one lever control (no separate shut-off lever). Other then some very unusual wear on the throttle shaft - I assume you are missing some spacers or have a damaged governor spring.
a247823.jpg
 
Thank you. I will get a new speed tube, replace it and see what I get that way. If that does not help, I will post pictures of the pump to see if anyone thinks there may be parts missing.
 

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