John Deere 3 pt. hitch and PTO

[Walter Buller]

A couple of years ago a man from a deer camp brought me a pretty beat up and neglected John Deere 1120 diesel to sell for them. I used to have a tractor refurbishing business. I have not seen this man since that day, don't remember his name, and don't know his phone number. So, yesterday I decided to try to crank it, finally getting it started by pulling it this afternoon. I have never owned a John Deere tractor, except for the few I bought and sold over the years. When this man first brought this tractor to me, the 3 pt. hitch didn't work, but after cranking it this time, it started working just fine. I picked up the lift arms and left them there. As I was trying to figure out how to use all the levers and such, I noticed a short lever, maybe 3-4 inches long, on the floor, right in front of the seat. I turned it counterclockwise. As soon as I did, the lift arms dropped and would not come back up even after returning that lever to its original position. I also apparently could not find the correct lever to engage the PTO. Not knowing whether this tractor might have a hydraulic PTO, I removed the plug on top of the housing just behind the seat and a little to the right, using a half inch socket drive with an extension. I also removed the 9/16ths square plug about a foot beneath the fill plug, figuring that this smaller plug must be the full indicator. I poured 2 gallons of hydraulic oil into the hole for the top plug but still did not see any oil running out of the lower hole. I of course would be well served to get an operator's manual for this tractor, but I have no way of knowing whether I'll ever see the owner again. So, if any of you guys could spare a few minutes to comment on my problems here, it would be very much appreciated.

 

[wore out]

You can download the Operator's Manual (OML29423 for the English version) in .pdf format for FREE at the John Deere Bookstore, https://techpubs.deere.com/en-us/Search/Equipment.

It may take a little figuring out to get it to download, but it works, I did it and saved it for future reference.

 

[Tx Jim]

X2 on downloading free operators manual. One should not change setting on bolt with lock nut that can be viewed by removing hyd oil filler cap unless one is following load/depth mechanism adjustment procedures outlined in 1120 technical manual. Round pipe plug in LH rear of trans case was utilized to access parking brake adjustment if applicable.

IMHO one should only add hyd oil to trans case after checking oil level with dipstick & determining level is low.
Photos below show some 1120 operators manual service information.

This post was edited by Tx Jim on 12/09/2022 at 05:28 am.

 

[Walter Buller]

Thanks so much wore out.

 

[Walter Buller]

Thanks a million Tx Jim for all that pertinent info. So, that little lever on the floor, #16 in the picture, is the Rate of drop lever. Well, okay. I discovered that turning it counterclockwise increases the
rate of drop to immediate. So why doesn't turning it back to it's original position allow the lift arms to work like they're supposed to? Should I gently tap it in that direction with a hammer to be sure it's
closed?

 

[Tx Jim]

Rate of drop screw turned completely clockwise will keep 3pt from lowering but has no affect on 3pt ability to raise.

#1 you should have never loosened locknut that can be seen when hyd oil filler cap has been removed.
#2 my guess is cam follower(shaded part) isn't in correct position in the slot in 3 pt control linkage or spring(item 8) is broken or has become loose

 

[Walter Buller]

Relative to your point # 2, I will check those items. Relative to your point #1, I did not loosen any locknut in that location or anywhere else on the tractor. And apparently there is something wrong with the
PTO because adjusting the PTO lever between the shifters up or down as per the schematic does nothing.

 

[Tx Jim]

Please forgive me for my poor reading comprehension concerning #1. I suggest to remove cowling that gearshift levers protrude through & check trans pump hyd pressure on shift cover. Pressure should around 155 psi. Does this tractor have a lever on LH side of trans case resembling item 1? If it must be in forward position for pto to be powered by tractors engine.

Tractors built for sales in European countries have some different controls than tractors built for sales in N America that I'm acquainted with.

This post was edited by Tx Jim on 12/09/2022 at 09:41 am.

 

[Walter Buller]

I downloaded the operators manual. It identified that short lever under the seat on the floor as the rate of drop lever, the speed at which the lift arms go down. Turning clockwise decreases the speed. Turning
counterclockwise increases it. Question: How can it possibly make any difference when it isn't connected to anything? I turned it all the way counterclockwise until it unscrewed completely out of the hole. All
there is is a chrome button immediately under the lever that looks sort of like a take off point for a temperature sending unit. How can that have anything to do with the lift arms?

 

[Tx Jim]

Turning bolt CW pushes a ball(item 6) against a beveled orifice in 3 pt piston housing controlling 3 pt valve "return oil flow".

 

[Walter Buller]

Well, looking into that hole and seeing that ball told me that it must be like you said. Therefore, shouldn't turning that lever in the other direction, i.e., CCW, allow the ball to move up a little so the oil
flow increases, allowing the lift arms to go down faster? That must be how it's supposed to work, but if that is true, shouldn't I be able to push this little ball down after removing the lever? I can't. The
manual says that this lever only determines how fast your implements drop, not how fast they come up. So why won't the lift arms come up now? I changed the hydraulic fluid and cleaned off the screen but that
didn't matter either. Is it possible that whatever is under the ball is stuck so the position of the lever isn't going to make any difference? I was unable to remove the ball even though it obviously isn't
stuck because I don't have anything that can grab it down in that hole, and it must be stainless because it isn't magnetic. Could this problem be related to the PTO not working? .

 

[Tx Jim]

Gravity holds ball against it's seat & hyd pressure will move ball off its seat unless bolt is screwed down to hold ball on it's seat.

3pt operation & pto operation aren't really closely related. Pto operates from trans pump pressure(155 psi) & 3 pt operates from frt hyd pump pressure(2250 psi

 

[Jim.ME]

Jim,

I understand the two are not closely related but the transmission pump gives the main hydraulic pump charge oil, doesn't it? If the tractor has been setting, would it be worth pouring a gallon or so of Hy Gard into the reservoir above the pump? If the transmission pump is weak or lost prime might that be enough to get things flowing? If the PTO turns, with a load against it, that will indicate it has some transmission pressure and should be charging the front pump, correct? Could the sump screen and hydraulic filter be plugged?

How cold is it where the tractor is? Could it have ice in the sump preventing it from picking up oil? Just thoughts.

 

[Walter Buller]

Here in Louisiana it almost never freezes. It's been in the 70's here lately. It's interesting that the 3 pt. lift arms would not come up over a year ago when the tractor was first brought here, but when I
finally cranked it by pulling it the other day, the 3 pt. hitch worked fine until I turned that short lever on the floor under the front of the seat, although I suppose that could have just been a coincidence.
A mechanic at a nearby JD dealership said that if I unscrew that short lever from the floor and then crank the tractor, hyd. oil should come flying out of there when I move the 3 pt. hitch lever backward but
it doesn't. He said the problem must be internal, just as the problem with the PTO must be. .

 

[Tx Jim]

Jim.ME
Walter stated 3 pt operated then stopped operating so I overlooked possibly non-operating trans pump. I agree it's possible trans pump is not operating.

I suggest Walter remove hyd fiter cap with a container to catch oil & rotate engine crankshaft with starter for 15 seconds. There should be 1-1/4 gallons of hyd oil in container. I also suggest for Walter to check/clean hyd oil suction screen.

 

[Jim.ME]

When was the last time the suction screen in the transmission was cleaned and the hydraulic filter changed?

 

[Walter Buller]

3 days ago. Changed the oil too.

 

[Tx Jim]

Then I highly recommend performing the trans pump flow test I suggested in an earlier reply. Also check to determine that filter relief valve(items 18-20) isn't stuck open.