# 2840 Issues



## Hawkins2015 (Feb 22, 2021)

Hey guys. New member and just bought my first JD. A 2840 with 148 loader and supposedly 1500 original hours. 

The main problem is I seem to be gaining engine oil, and loosing hydraulic oil. The engine oil dipstick does not smell like fuel. Maybe the two are unrelated, but where would these two cross? Considering it has a dry clutch, the only other place I can think of is a cooler. 

Second problem is the loader not only leaks off, but after a few minutes, almost raises the tractor off the ground. Guessing this problem is in the valve by the levers, and just needs rebuilt. I’d really like to have a joystick style over the dual sticks, but can’t seem to find the joystick style anywhere. 

Third is I can’t seem to get the differential lock to engage. With pressure from both my foot and hand, the lever won’t move. Am I doing something wrong in assuming it’s supposed to rock forward?


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## Fedup (Feb 25, 2014)

It's doubtful the hydraulic fluid is transferring into the engine. I'm not aware of any connection between the two. Your engine oil rising is more likely fuel. You need to monitor that closely, since fuel diluted oil can be a major problem/expense if not soon corrected. 

The loader/valve problem could be any number of things. I've seen all manner of plumbing arrangements on John Deere tractors of that vintage when it comes to operating a loader. How your is set up needs to be explained before much help can be offered there. Is there a dedicated loader valve? Is it supplied by a remote valve or is it tied into the system? Is it a closed center valve? Maybe the loader is operated strictly with the factory remote valves through the couplers on the back. ????

The dif lock issue could be as simple as stuck/rusted linkage. Does anything move either way when you try to operate the pedal?


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## Tx Jim (Jul 28, 2020)

Welcome to the Tractor Forum
I agree with Fedup that there's no connection between engine & trans for either or both type oils to mix together, Hyd oil cooler is cooled by airflow through the fins. What type valve controls FEL(scv or ind dual spool)? Shown below is a JS valve & it requires a closed center plug to operate correctly on a JD 2840


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## Hawkins2015 (Feb 22, 2021)

I’ll look at the loader valve to confirm. 

But I’m guessing that since this thing smokes when running, it’s a safe bet that it’s the injectors letting loose?


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## Fedup (Feb 25, 2014)

Not a "safe bet" at all. Just because an engine smokes while running doesn't necessarily point to injectors. The color and severity of the smoke, operating conditions under which it starts, changes, increases, decreases, etc? Any/all could be indicators. Starting and running characteristics, oil consumption, breather vent blow by, even certain oil and fuel leaks can be a factor in some cases.


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## Tx Jim (Jul 28, 2020)

I agree smoking could be clogged air cleaner or associated components or incorrect injector pump timing.


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## LouNY (Dec 15, 2016)

Were is the hydraulic pump located on this tractor,
of a shaft in front of the engine,
or is it mounted on the engine,
or in the transmission case?


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## Tx Jim (Jul 28, 2020)

Frt hyd pump that was designed to create 2250 psi is located under/in front of radiator driven by engine crankshaft via a drive coupler. Trans pump that lubricates trans brgs/gears & operates IPTO & hyd hi-lo plus supplies oil to frt hyd pump is in front of transmission.


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## Hawkins2015 (Feb 22, 2021)

Fedup said:


> Not a "safe bet" at all. Just because an engine smokes while running doesn't necessarily point to injectors. The color and severity of the smoke, operating conditions under which it starts, changes, increases, decreases, etc? Any/all could be indicators. Starting and running characteristics, oil consumption, breather vent blow by, even certain oil and fuel leaks can be a factor in some cases.


It smokes at startup until it gets warm. After that, the only smoke to speak of is white, moderate when a load is pushing against the engine, like going down a hill. 

Tractor is relatively hard starting. Under 40 degrees and I really have to plug it in. 

I don’t think the hydraulic leak is as serious as I mentioned earlier. So I can see them being separate issues. Engine oil is still “gaining” probably a quart in 10 hours. 

I will take a picture of the loader valve as well, so you all can see what it is.


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## Tx Jim (Jul 28, 2020)

Engine oil level increasing indicates diesel is entering crankcase. Easiest thing to check for is faulty fuel transfer pump. If TP isn't the problem then I'll bet seals on inj pump drive shaft have failed. On fuel related smoke I'll suggest to check inj pump timing.


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## Hawkins2015 (Feb 22, 2021)

Got a lift pump for it. Plan to put it on next week. It does, however, have a sediment bowl where mine does not. And the bowl will be upside down from what it’s supposed to be. Well see if it works. 

Here is a picture of the valve for the loader. I’m guessing that there is a reseal kit that will solve my problems. 











The rods go up to the levers on the platform. 
Thanks for help so far. Almost have this thing fixed up enough to be ready for hay season. 


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## Tx Jim (Jul 28, 2020)

i think your FEL control valve is a Cessna brand. If my guess is correct valve seal kit is shown in photo below. Some older style fuel lift pump had glass bowl that was upside down when pump was mounted on engine.


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## Hawkins2015 (Feb 22, 2021)

Lift pump solved the oil issue. Thanks for that. 

Now, in hay season, I’ve got another problem. I know this style tractor is notorious for hydraulic problems. Ever since I’ve bought the tractor, theres a strong chatter in the lines at idle. But once you throttle up a little, it goes away. 
However, I have now found that once I’ve been mowing/baling for several hours the chatter returns and knocks out all of my hydraulics. I notice that the steering column is extremely hot, so I’m guessing it has something to do with heating up the oil. 
I hosed out both coolers and that helped things, but didn’t solve anything. Once this happens I have to let the tractor sit for a half hour or so and I can take off again. 

Looking for some wisdom on what I need to check first. I keep hearing about an internal line that cracks, and that’s what my problem is. But I’d really like to narrow it down before I split the thing. 

Any advice or good reading is appreciated.


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## Tx Jim (Jul 28, 2020)

I'll suggest to disconnect power steering supply line then cap pressure line & operate tractor with PS disabled to see if hyd oil is cooler while harvesting hay .


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## Fedup (Feb 25, 2014)

Good guess on the steering column heat having a connection to the current problem. If the steering works okay (when all else is working as well) then the steering valve probably needs seals. Not a job for a novice, so I would suggest you seek out someone locally who knows the system and has "been there, done that" before. Maybe a Deere dealer or independent shop. Someone you can have some faith in, not someone who "thinks" he can, but has never actually done one. 

Removing and installing the column/valve assembly is just nuts and bolts, you can do that part should you choose. If you can't find anyone locally, there are people that can do the work if you care to ship the valve back and forth.


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## Tx Jim (Jul 28, 2020)

Fedup
I think 1 or more of the 6 large o-rings that seal the 2 valve bodies inside the cast iron steering housing are probably leaking. I think a person with moderate mechanical skills can replace those 6 o-rings with the aid of a good work light & a long stiff piece of wire or small rod. Important part is be sure each new o-ring fits in each appropriate groove inside housing. 
I'll caution if 1 or both valve bodies are removed from shaft one needs to keep inventory of location of each shim for valve bodies. 

One can renew the 6 o-rings without removing the cast iron housing from tractor by removing steering wheel & adjuster nut then turn shaft with both valve control bodies CCW out of cast iron housing. Then R&R the 6 o-rings

JD utility tractor power steering valve isn't near as complicated as a 3020 or 4020 steering valve


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## pogobill (Jan 31, 2012)

Something I'd be a little leery of trying! Maybe with a manual and take lots of pictures of the disassembly.


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## Fedup (Feb 25, 2014)

I guess my skills are far less than moderate. I spent the better part of four hours one day trying to install the six mentioned O rings, managed to get only one in place, and that one was an accident. Manual or no manual I will probably never attempt another. The local dealership put them in and assembled the valve for $80 labor. That's my take on it.


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## Tx Jim (Jul 28, 2020)

Fedup
I'm recalling 35-40+ yrs ago so you could be correct!!
Back when I served as a JD dealer service manager I had so called technicians under my supervision that couldn't repair/adjust complicated JD SCV & steering valves correctly the 1st few attempts.


I remember the 6 o-rings are no easy task to replace but not impossible for someone with patience. And IIRC o-rings are easier to R&R with cast iron housing setting on a work bench. My guess depending on """"how many yrs ago you had dealer tech replace those 6 & assembled valve for $80""" that JD dealer service manager didn't consider R&R of the o-rings that difficult either.


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## Tx Jim (Jul 28, 2020)

pogobill said:


> Something I'd be a little leery of trying! Maybe with a manual and take lots of pictures of the disassembly.


JD utility tractor from '65-'82 steering valve assemblies are a lot simpler than their counterparts built in Waterloo in the similar time frame('61-'75). I'm referring to tractors built for sales in N. America that I'm familiar with not the units generally built for European sales


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## Hawkins2015 (Feb 22, 2021)

Tx Jim said:


> I'll suggest to disconnect power steering supply line then cap pressure line & operate tractor with PS disabled to see if hyd oil is cooler while harvesting hay .


I can try to disconnect and see what happens. Is it possible though that the steering column is hot just because the oil is hot? I mean the oil is circulating through, so it makes sense to me that it could be coming from anywhere, because all the hydraulic components are extremely hot. 


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## Tx Jim (Jul 28, 2020)

Technically hyd oil should stop at steering valve when steering wheel isn't moving & only proceed when steering wheel is turning. Closed center hyd system is designed for oil to STOP at control valve until control valve is opened allowing hyd oil to proceed. Probably a high pressure internal leak is causing oil to heat.


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## SidecarFlip (Mar 25, 2021)

One thing I'd do when you are done fiddling with hay is, pull the injectors and do a compression test. Willing to bet you have weak or glazed rings and possible valve issues as well. Was the overhead ever adjusted or do you even know?


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## Tx Jim (Jul 28, 2020)

SidecarFlip said:


> One thing I'd do when you are done fiddling with hay is, pull the injectors and do a compression test. Willing to bet you have weak or glazed rings and possible valve issues as well. Was the overhead ever adjusted or do you even know?


It would surprise me with 1500 hrs of use that engine would have a compression problem unless someone has been overdosing engine with starter fluid. I strongly advise to check inj pump timing.


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## SidecarFlip (Mar 25, 2021)

Could be a number of issues but white smoke when operating is indicative of something wrong and of course the owner don't know the history of the tractor and how it was used / abused either. He said it was hard starting. Diesels need compression to fire and atomized fuel at the right time so something is wrong mechanically.


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## Tx Jim (Jul 28, 2020)

I sold New JD 2840 tractors & they were hard starting more due to hyd pump not going into de-stroke mode than due to engine problems. The ""something wrong with diesel engine smoking"" could be as simple as Injection Pump not timed correctly not something to do with compression!!!


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## SidecarFlip (Mar 25, 2021)

Every option is on the table....

Curious, do all tractors 'destroke' the hydraulic pump when starting? Don't think my Kubota's do, the multi segment pump is a direct drive off the front gear train?


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## Tx Jim (Jul 28, 2020)

Your Kubota has open center hyd's with no need for a destroking screw. JD 2840 has closed center hyd's that was designed to de-stroke automatically when there was no demand for extra hyd pressure BUT when internal hyd leaks rear their ugly head this ceases. When CC hyd pump loses it's capability to de-stroke & drag on starter is increased one needs to manually or electronically de-stroke the CC hyd pump as an engine starting aid.


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## SidecarFlip (Mar 25, 2021)

Interesting, thanks. I'm not well versed in how hydraulics work and if I had an issue, I'd call my dealer for advise.

I do have something going on with the open station and was going to post it up anyway, but I'll ask here, maybe you can tell me...

The OS (6000 hours) has developed a whine in the hydraulic system, not there constantly, comes and goes and if I put my hand on the hard line that comes off the pump, I can feel it vibrate. I can also hear it under the dash so I'm thinking it might be time to rebuild the orbital steering pump. Steering is not impacted at all and no leaks anywhere, in fact the entire tractor is leak free.

I don't like the whine. Maybe it's time for a trip to the dealer and have Dennis rebuild the orbital steering unit and yes I have the WSM. No issues with fluid temperature either. gets warm, never hot and the oil cooler is clean. Fluid isn't low either. Right at the top of the dip stick (15 gallons) and I just changed it and the filters in the spring.

Opinion?


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## Tx Jim (Jul 28, 2020)

My guess is rebuilding steering valve possibly wouldn't solve the whine but your technician would have better knowledge. How many hrs of use since hyd filters were changed probably not very many? The majority of my hyd experience is with closed not open-center systems.


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## SidecarFlip (Mar 25, 2021)

Full service this spring including both high and low pressure filters (Kubota of course) and 15 gallons of Chevron YHC synthetic All Weather fluid.

I don't have the service history on this one because I bought it used from of all things a JD dealer and not local either. Had them deliver it to the farm before my dealer fetched it from here. While it was here, I changed all the fluids, the case appeared to have Hy Guard in it, it was half full and filthy, the motor oil was black and interestingly, it appeared to have the original fuel filter on it, even my dealer was amazed that it even ran. Kubota paints their filters at the factory grey and it was grey. Had the dealer address all the issues and repair them. That was 2 years ago. really don't get worked hard. Just does the raking and rarely has the chopper (batwing) attached.

Just started making the whine sound this spring. It is a 2002 and it has a fair amount of hours (6000) so I have fully expected some issues to arise. Runs very well and is very frugal on diesel, runs clean, no smoke and like I said, I rarely get it up on boost.

Dennis put it on the dyno at the shop and it dyno'd at 95 pto which is a bit more than what the stock number is. I think stock power is around 85.

Thinking this winter, it's off to the dealer and have Dennis diagnose and repair it. I've read the steering orbital motor is a hard rebuild and a reman is expensive.

The other one has to go in as well. Bought a new Kneverland round bailer (full electronics) and the electronic package that is in it now has to come out and be replaced.

One difference between this one and my other one is, if I don't 'glow' this one a bit (no matter what the ambient is), it will start and stall once. My other one don't do that at all. As hot as it is, the other one dead cranks and pops right off.

Like I said, have no clue about it's previous life and what abuse it had. I'm sure it was by the looks of the bucket that came with it. Was told it was on a dairy farm. probably spent it's life piling manure. The air filter element was solid with filth. Even the inner was filthy. All replaced with new.

Other than the cab, they are identical, 2 speed pto's, creep gears, cast centers and triple outlets on the back but this one has the optional down exhaust, the other one is through the hood. Kind of like the down pipe as it don't obstruct your forward vision.

Needs new shoes too. In fact both need new shoes. Putting that off as new shoes will be over 10 grand for the pair.


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## Hawkins2015 (Feb 22, 2021)

I don’t see this (my issue) stemming from engine problems. I have no problems starting until temps get down to freezing. And especially after I hosed the heat exchangers out, engine coolant temp stays below halfway on the gauge. 

So maybe someone can answer me this. 
Why does an internal leak or the oil getting hot send the pump into a destroke? That sounds like what’s happening to me after 3-4 hours. Lines chatter and I slowly lose all hydraulics until I shut down and let it sit for an hour. 


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## Tx Jim (Jul 28, 2020)

Trans pump only has a certain amount of GPM of oil it can pump. Once internal leak exceeds a large portion of trans pump GPM then frt pump starves for oil supply then starts cavitation. Closed center frt pump has no ability to suck oil IE it must have oil furnished therefore the need for a charge(trans) pump. Higher temp oil creates a larger internal GPM leak.


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## Hawkins2015 (Feb 22, 2021)

So what's the procedure for starting to trace internal leaks?

Hoping this isn't the infamous cracked internal line, but even if it is, what will keep the replacement from doing the same thing?

Anyone have any good reads on this issue?


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## Tx Jim (Jul 28, 2020)

Have you looked inside open hyd filler hole for moving oil when 3 pt is fully raised & engine is running? Does this tractor have a FEL? Best tools for hyd diagnostics are a flow-rater, 5000# & 300# gauges. There should be many threads on the WWW about diagnosing/repairing JD closed center hyd systems


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## Hawkins2015 (Feb 22, 2021)

So it’s been awhile, but here’s an update. 

Engine running, 3-point raised or lowered, I see no oil through the filler hole. 

I took the loader off to access the lines and valve easier. I also plowed up and am going to reseed 2 acres, and didn’t need the loader. Noticed that even though I was working the tractor hard and engine coolant temp was warm, I never had the hydraulics act up. In the hay field, after running for 3 hours or so the hyd oil would get VERY hot, and I could not operate anything hydraulics. During plowing for 4 hours, steering shaft was still cool.

So here is my two thoughts. 
1. Taking the loader off and no longer having a leaking FEL valve solved the issue. Currently working on getting the valve off and resealing. 
2. Hay season problems occurred at 90-95 degrees. Last week I was plowing in 60 degree sunshine. Maybe it was cool enough that it couldn’t get hot. 

Thoughts?


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## Tx Jim (Jul 28, 2020)

What type valve was utilized to control frt end loader? Sounds as if it wasn't designed for 2840 closed center hyd system or the internal seal on closed center conversion plug has failed OR pressure relief valve on FEL control valve if applicable isn't set to stay seated at 2250+ psi.


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## Hawkins2015 (Feb 22, 2021)

Tx Jim said:


> i think your FEL control valve is a Cessna brand. If my guess is correct valve seal kit is shown in photo below. Some older style fuel lift pump had glass bowl that was upside down when pump was mounted on engine.


Guess this is what you’re asking. Just got it pulled off, and I don’t see a name brand. Just numbers. JD 148 loader that is supplied from the block under right side platform. Lines continue up front. Return from loader goes straight to filter housing. 


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## Tx Jim (Jul 28, 2020)

Simple test with hyd pressure or compressed air applied to FEL valve "in port" with valve control lever(s) in neutral. IF when pressure is applied to in port a large volume of oil/air exits valve "return port" then valve spool to housing clearance is too much or if applicable control valve relief valve isn't holding system pressure or closed center conversion plug if applicable has failed


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## Hawkins2015 (Feb 22, 2021)

Really irritated now. Resealed the valve, and noticed nothing glaringly obvious wrong. O-rings were a little brittle, but not bad. Spool looked OK. 

Put loader back on and there is no difference. Guess I should have ran the tests with the valve still off. 

Previous owner told me that the loader cylinders had just been repacked, but it seems like he lied about other things so who know if that’s true. Seems like my only options are remove valve again and see if Tx Jim’s test reveal anything, or repack the loader cylinders. 


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## Fedup (Feb 25, 2014)

"Put loader back on and there is no difference". What does that mean?

If the loader valve is still suspect, then simply remove the return line from the valve to filter base (wherever it's most convenient) and start the tractor. If the valve is a problem you will know it pretty quickly.


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## LouNY (Dec 15, 2016)

I would say from the fact that with the loader removed the system worked good and did not over heat or chatter
that it is most likely the valve. As was previously mentioned either the spools or the closed center plug is not working or the relief valve is dumping oil.
So to start with just pull the return line off the valve or the tractor, if you take it off the tractor you can wire it so it goes in a bucket.
Start the tractor and see how much oil comes out the return.


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## Tx Jim (Jul 28, 2020)

My guess is repacking cylinders will be a waste of time & $$$$. I suggest again to do as others I suggested to perform simple test that will cost very little in time & $$$$


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## Hawkins2015 (Feb 22, 2021)

Update on this thread. 

Wasted money on repacking the cylinders. Made no difference. Points to those who guessed right.

I ended up just removing the loader for the majority of hay season since my father in law bought another tractor with a loader. 

Replaced the valve and it seems all issues are solved, for now. 
The hydraulics have not started chattering at low idle like it normally did. We’ll have to wait until next season to find out about losing all functions when hot. 


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## Tx Jim (Jul 28, 2020)

Thanks for update. You can test hyd system by placing a jumper hose with 2 male hyd tips plugged into a set of rear breakaway couplers. Start engine activate scv control lever for a short period of time. This method oil flow will rapidly heat oil, cycle oil until one can feel heat in hose, then place scv control lever in neutral position then operate FEL control valve


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