JD 2140 Hydraulic Judder & Transmission

[Battler86]

Hi all,

Our JD 2140 is suffering the dreaded hydraulic shakes.... lift arms judder, stiff steering, loader and remote cylinders all tremble when the main pump runs dry. Revving right up usually sorts the steering, but loader and running anything on the remotes is a headache. As expected she's worse when hot due to thinner oil, but the problem is evident when cold. It doesn't drop out of PTO, 4WD or HiLo what so ever. When warm it's a nightmare to shift to high, but once in, it'll stay in. Basically, it's all good until the front oil tank runs dry and the main pump begins to cavitate.

Looking towards the transmission pump....

Filters changed, also checked filter bypass valve, steering priority and surge relief which are all good. Transmission pump suction screen relatively clean (apart from bits of clutch plate). When I checked the 2 stage pressure reg valve in the transmission cover I noticed the outer spring measures 124mm as opposed to JD's stated 129mm which will affect valve opening pressure... this will be replaced.

Next, I checked the flow on the feed to the main pump which was between 0lpm and around 20lpm (Should be 54lpm - 15lpm for the hilo)

So, we split the tractor before the transmission, then at the bell housing taking the whole casting out (Doing the clutch while we're at it).

None of the internal steel pipes are split / cracked and the O-rings don't look too bad. I've stripped out and pulled apart the transmission pump, HiLo, PTO and 4WD clutches. The HiLo friction plates are in a real mess, there's no 'frodo' material on them. At least that explains why selecting hi when warm was a nightmare.

None of the clutch pack plates look too clever, so they'll all be changed along with seals, O-rings etc.

Few questions below if anyone can help:

1. Could the lack of material on the HiLo selector clutch plates cause the piston to push out excessively leading to oil running past the piston ring and to sump? Thus, partly contributing to the starvation of the main pump?

2. I also noticed the spacer in the 4WD clutch which stood out (JD P/N: L38692). There is a recess that looks to be worn into one side leaving a small lip for the clutch plate to sit. I can't tell if this is machined or serious wear. Does anyone have any experience with this? (see attached pics)

3. Pinion gear (JD P/N: AL28751) from the HiLo clutch looks worn inside. It almost looks like a weld on the inside outer with head ground off. (see pic) It may be nothing, it may be something.

4. Transmission pump gears have a little scouring, nothing major. Will replace as it's out. But any thoughts appreciated (see pics).

I just want to be sure I've covered everything while it's apart. Clutch packs I'm not worried about as all wearing parts will be changed. But I want to make sure I've cured the hydraulic issue. Moving bales is a nightmare! Once it's back together it ain't coming apart again!

Thanks in advance

 

[traineefarmer]

We had a 40 series suffer similar when a seal failed in the rockshaft control valve causing oil loss from the high pressure system. Is the main pump reaching pressure and going out of stroke?

Have you pressure tested the internal pipes?

Where does your loader valve return the oil to? Some have a flow return to the filter and a dump return to the transmission case to avoid the pressure rise caused by the filter supply. If the valve has an internal fault causing the circulating flow to dump to the case you would get your symptoms.

 

[Phil P]

No 1, the worn plates would only make it slip not lose pressure. Re seal the two pistons in the hi/lo as the do perish, you’ll need a press for the bevel springs.

No 2, yes the spacer is worn, you’ll need try and measure the height as there’s a couple of different sizes. If it gets to worn the mfwd will drag.

No 3, it’s fine that’s how it’s supposed to look

No 4, I’ve seen worse! Did you pressure test system and lube before splitting? Should have 25 bar on system and a minimum of 3 bar lube.

As @traineefarmer says they can leak in the top cover lift housing and use all the oil up, there’s also a bolt that goes in the front of the housing to hold the lift cylinder tight against the seals, check that hasn’t snapped.
Ive also known the ends of the pistons in the main hydraulic pump to ware off and it pumps oil back to sump. Could be worth checking the pump poppet valve springs also.

 

[Battler86]

Thanks for the reply chaps.

While the cabs off I'll check the lift housing, the arms do drop overnight. Where is the rockshaft control valve located? I'll also check the loader valve block. Forgot to mention we changed the main pump last year as we suspected worn pistons. But yep, its holding standby pressure at 190 bar and swashing back.

Tested the steel internal pipes with the airline to 8 bar.... No cracks.

Transmission pressures were fine if I remember correctly. The lack of flow was baffling and indicated an internal leak somewhere or a worn transmission pump.

The loader return was piped into the bottom of trans filter bowl, but I changed it to run straight into the back end thinking that may be causing issues. In fact, it had no effect. When the tractor goes back together I'll run the return back into the filter bowl again as it can't do any harm regenerating the oil.

 

[traineefarmer]

Rockshaft control valve is bolted inside the top cover. We had to replace the whole block as the casting had worn.

 

[Battler86]

Thanks for the heads up traineefarmer. Rock shaft next job once the clutch packs are back in.

Talking of clutch packs..... I'm currently building up the HiLo. Has anyone any tips on pushing the piston back into the housing without damaging the poly seals? I was thinking of using shim steel greased up to guide the piston in, then pull it out from around the seal. Unless anyones tried anything different?

The original steel piston rings L62272 and L62161 have now been superseded with polyurethane seals. They'll give a better seal, but they look like a ball ache to fit without splitting or damaging. Not much of a chamfer on the housing to guide me in either!

 

[Phil P]

Thanks for the heads up traineefarmer. Rock shaft next job once the clutch packs are back in.

Talking of clutch packs..... I'm currently building up the HiLo. Has anyone any tips on pushing the piston back into the housing without damaging the poly seals? I was thinking of using shim steel greased up to guide the piston in, then pull it out from around the seal. Unless anyones tried anything different?

The original steel piston rings L62272 and L62161 have now been superseded with polyurethane seals. They'll give a better seal, but they look like a ball ache to fit without splitting or damaging. Not much of a chamfer on the housing to guide me in either!

They’re a pita to get in! I usually put it on the press so I can hold the piston down and square. I with a bit of light pressure on the piston I then use a rounded seal pick to guide the seal lip past the edge of the housing a bit at a time.
you have to just go steady and do a bit at a time and keep checking it hasn’t popped back out at the other side before pushing it down further. It does take a bit of pressure to get it over the inner seal.
Hope that makes a bit of sense.

 

[Ioan annwyl]

Check tow cup, steel plugs tend to blow out and also valve seat. Old style NLA so need to change to 50 series type.
This will cause low lube pressure.

 

[Battler86]

Managed to get the hilo piston in using steel shim covered in grease, a lightly feathered press and a flat screw driver to push the seal in. Good combination of the 3 and it wasn't too bad.

PTO and HiLo are both back in and tested with the airline.

When I put air pressure into the FWD pipe on the top far left of the shift cover, while blocking the outlet on the bottom of the clutch, air comes through the center of the clutch? Not much but enough. Is this right? I thought the FWD inlet from the shift cover was direct to FWD clutch pack.

 

[Tractortech]

Now Then..
The 'leak' on the MFWD line is to lube the Hi Lo.
Back in the day, JD supplied a shepherd's crook shaped bit of MIG type wire to restrict the orifice so as to improve hydraulic performance..

 

[pail of ale]

Did u do the gaskets in the shift cover?

 

[Battler86]

Sorry on the late reply chaps. Yep, I did the shift cover gaskets. Also found a broken spring in the Hi shift detent lever.

Got her built back up and running finally, and its a different machine so far. Engaged in Hi with PTO and MFWD, steering is smooth and the lift arms have never moved so well.

Put the flow tester on the rear remotes and the front pumps producing 45lpm at 2500 rpm @ 50 bar and 40lpm @ 170 bar until I move the steering, as expected.

On the whole a good result, although I'm having issues with wiring / engine now so haven't really done any work with it yet.

 

[Goatford]

We had a 40 series suffer similar when a seal failed in the rockshaft control valve causing oil loss from the high pressure system. Is the main pump reaching pressure and going out of stroke?

Have you pressure tested the internal pipes?

Where does your loader valve return the oil to? Some have a flow return to the filter and a dump return to the transmission case to avoid the pressure rise caused by the filter supply. If the valve has an internal fault causing the circulating flow to dump to the case you would get your symptoms.

Hello Trainee farmer. I've also got the loft arm judders. I've changed the back end oils, changed all the filters, cleaned the priority valve and cleaned the bypass valve. I'm now thinking it's the rockshaft control valve as you have described. I've a 2140 1983 2wd. Is it a cab off job to fix?

 

[Tractortech]

Hello Trainee farmer. I've also got the loft arm judders. I've changed the back end oils, changed all the filters, cleaned the priority valve and cleaned the bypass valve. I'm now thinking it's the rockshaft control valve as you have described. I've a 2140 1983 2wd. Is it a cab off job to fix?

What cab do you have??

 

[Goatford]

What cab do you have??

SG2

 

[Cowabunga]

I had the judder and excessive oil heating due to a control valve oil seal leaking. This was at about 5000 hours. While it was apart the Hi-Lo clutch was shot and changed and so was the PTO clutch pack. One or both were upgraded with an extra steel and friction disc. It’s done something like 12,000 hours now with no further issue in those parts. As an indicator of the kind of work it did, the ARM auto hitch had been built up at least twice by these hours and at 5500 hours a complete new autohitch was fitted and the old one scrapped. That’s not just the combined drawbar and hook but the whole complete hitch.
At 9500 hours, not long before I sold it, the main front piston pump wore out and was replaced by an used one from a tractor with half the hours and it still works fine. The tractor now belongs to my silage contractor and until this year it was on his large Pötinger twin rotor rake. Its driver is past 80 and found the clutch heavy and lack of air con uncomfortable so he now has a 6620 I think it is.

 

[Tractortech]

SG2

SG2 is a cab off job. Do as much as you can while it's off. 50 series lift and lower valves in the rockshaft, check for missing ball bearings in the 'tow cup' Hi-Lo, PTO clutch, MFWD release ring, low pressure oil line updates and seals etc..

 

[Cowabunga]

Lets not forget brakes while we are at it.

 

[MontyK]

Now Then..
The 'leak' on the MFWD line is to lube the Hi Lo.
Back in the day, JD supplied a shepherd's crook shaped bit of MIG type wire to restrict the orifice so as to improve hydraulic performance..

Is that the one you shove down the pipe? Very long time since I've worked on them.

 

[Goatford]

SG2 is a cab off job. Do as much as you can while it's off. 50 series lift and lower valves in the rockshaft, check for missing ball bearings in the 'tow cup' Hi-Lo, PTO clutch, MFWD release ring, low pressure oil line updates and seals etc..

Thanks for the reply. Not sure I can face fixing it at this stage. I've been working on it so long I can't bring myself to keep working at it.