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Discussion Starter #1 (Edited by Moderator)
Okay, right to the point. But first, why isn't a listing for the 30 series compact utility tractors? Ie: 1030,1630, 1830, 2130?

Problem: transmission difficult to shift into gears. I must time my engaging of the range with the engaging of ANY gear (1.2.3.4)

Symptoms and oddities.: When the Hi/lo is in Low, I can smoothly shift into any gear like its a new tractor. BUT, I loose hydraulic supply to all functions like steering and 3PH. I switch back into Hi and all hydraulic functions return to normal but it is again incredibly hard to place any of the gear levers back into neutral. Once in Neutral, very hard to put back in gear.

Hi Lo is working, I can feel the shift down and up.

Oh crap, here's a really bad symptom. Put the ol'e girl on the dyno and in Hi range I get 30 HP, Put her in Lo, HP immediately goes to 43HP.

I have split her and can confirm that All steel lines and free of cracks. Also all sealing rings are in-tacked, none broken or worn down. All castings where rings ride are smooth without any grooving from the sealing rings. Clutch discs, pistons and rings are excellent.

And lastly, when I drive in hi range just a few feet and I step on the clutch pedal, the tractor comes to a dead stop.

Almost feels like Hi and Lo are both pressurized when Im in Hi range. Perhaps that explains the HP loss?

Looking forward to hearing suggestions. I've been doing this line of work for quite a while but this one has me stumped.

Also main clutch/pressure plate have been replaced.

Thanks Dodgerrr.
 

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Moved to proper forum (this is not a SCUT) and edited curse word.

Welcome to GTT.
 
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Okay, right to the point. But first, why isn't a listing for the 30 series compact utility tractors? Ie: 1030,1630, 1830, 2130?Thanks Dodgerrr.
Welcome to GTT.
Actually a JD 1630 was classified by JD engineers as a utility not compact utility tractor. A JD 1630 tractor should have 50 HP on the pto. My guess is tractor coming to an abrupt stop when clutch pedal is depressed is caused from dragging brakes. IMHO hyd hi-lo needs to have hyd pressures checked in both ranges.
 

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First, for Hi/Lo you mean "rabbit/turtle" and have the left hand dash lever? Not to be confused with range I 1 -4 gears, or range II, 5 -8 gears?
I am puzzled why it's hard to shift in one range.

Lack of hydraulic functions indicate an internal leak, or filter relief valve has failed bleeding off pressure. Or bad transmission pump.

I had the pressure plate drive for the Hi Lo assembly fail and then trans pump would not pump.

I do not think both Hi and lo can be engaged at the same time, plus you say it shifts and you can feel the shift.
 
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Did you check suction screen and replace the trans filter?
 

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Discussion Starter #6
Tx Jim.

The weird thing is when in Lo (turtle) on the on the panel mounted shift lever, I can depress the clutch pedal and it will coast to a stop. When I'm in Hi (rabbit and depress the clutch pedal, that's when it rapidly stops.

Zebrafive.

Both the suction screen and transmission oil and filter have been replaced. I also removed and checked the filter bypass valve.

No pressure checks have been done. When dyno'd it made 40+hp. the pto brake works perfectly. Figured if both the pto clutch and brake work and I can hear and feel the HI/LO engage/disengage my pressures should be sufficient.

One other odd thing. Engine running at 1800 rpm in Lo range. then switch to Hi range...engine drops to 1400rpm. You can definitely hear the load on the engine.
 

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I suppose it's possible for hyd hi-lo shift valve spool to leak pressure between high & low speeds. This another good reason to check hyd hi-lo operating pressures.

Since tractor doesn't abruptly slow down when in low speed then that would eliminate dragging brakes as possible cause that I suggested.
 

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I would do the pressure checks TxJim suggested.
I would use TWO gauges to see if one dropped to zero when shifting between Hi & LO.
The small metal lines from the transmission pump to the Hi/Lo valve have o rings at each end, maybe one or more bad?
Also two larger lines from the valve.
Did you replace them when you had it apart?
Did you check all the oil lines high lighted? Replace all the o rings?

Maybe the a problem with the H/L valve? Key 11, 12, 7 13
 

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Zebrafive
I can't envision how failed o-rings on hyd hi-lo supply tubes could be causing the dragging in high range problem. Would you please explain your theory?
 

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Discussion Starter #10
I suppose it's possible for hyd hi-lo shift valve spool to leak pressure between high & low speeds. This another good reason to check hyd hi-lo operating pressures.

Since tractor doesn't abruptly slow down when in low speed then that would eliminate dragging brakes as possible cause that I suggested.
I don't think I can independently check both Hi and Lo pressures to the clutch disc's. I believe my shift cover has 3 ports. One for system pressure, One for PTO clutch and the other for PTO brake.
System pressure spec is 125-135 psi at 2100 rpm . I am getting that and a little more...closer to 145 at that rpm. However at idle I get 125 in Hi range and about 80 psi when shifted to lo range.
 

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Zebrafive
I can't envision how failed o-rings on hyd hi-lo supply tubes could be causing the dragging in high range problem. Would you please explain your theory?
Personally I believe that both clutch packs are being fed a supply of pressurized oil. Shaft #2 is hollow with a steel pipe inside. pressurized oil will either travel through the steel pipe and supply pressurized oil to the Hi range circuit. When shifting occurres to Lo range the oil pressure inside the steel tube drops to zero and now pressurized oil is fed through the hollow shaft to the Lo range clutch pack.

Every time I inserted and retracted the shaft, the sealing ring and retainer would stay inside the shaft. I use needle nose pliers to remove it and pop it back on.
I think this is how I am setting pressurized oil to both hi and low clutch packs.



Transmission shaft JD.jpg
 

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80 psi is low indicating an internal leak. Actually IIRC system pressure should be 155-165 psi. I think oil to control hyd hi-lo travels through the 2 tubes highlighted in yellow in Z5's photo. It's been many,many yrs(1987) since I viewed/studied the hyd flow chart in a JD utility tractor technical manual.
 

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I know on my 2940 the hi-lo circuit pressure is 160 psi on both hi and lo circuits. Your 125 and 80psi are both low. the 80 psi on hi could be the reason its dragging. On the 2940 when pressure drops below 125 the circuit is suppose to automatically kick it into lo range... warning that something is going wrong.
 

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Zebrafive
I can't envision how failed o-rings on hyd hi-lo supply tubes could be causing the dragging in high range problem. Would you please explain your theory?
Only thinking about the loss of hydraulics, and a source of a leak.

No idea about the dragging in hi.
 

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Personally I believe that both clutch packs are being fed a supply of pressurized oil. Shaft #2 is hollow with a steel pipe inside. pressurized oil will either travel through the steel pipe and supply pressurized oil to the Hi range circuit. When shifting occurres to Lo range the oil pressure inside the steel tube drops to zero and now pressurized oil is fed through the hollow shaft to the Lo range clutch pack.

Every time I inserted and retracted the shaft, the sealing ring and retainer would stay inside the shaft. I use needle nose pliers to remove it and pop it back on.
I think this is how I am setting pressurized oil to both hi and low clutch packs.



You might have the answer. I was guessing the spool was leaking between both Hi and Lo. Now I am thinking the leak is somewhere between shaft 2 and tube 3.

I think I would replace, with new, all the sealing rings on shaft 2 and tube 3, plus the retainer for 3. It should not be come off? :dunno:

I have never had shaft 3 out of shaft 2, once broke a sealing ring on shaft 2 when installing the shaft. Luckily I caught my error. and bought a new sealing ring and was more careful on the second try.
 

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I don't think I can independently check both Hi and Lo pressures to the clutch disc's. I believe my shift cover has 3 ports. One for system pressure, One for PTO clutch and the other for PTO brake.
System pressure spec is 125-135 psi at 2100 rpm . I am getting that and a little more...closer to 145 at that rpm. However at idle I get 125 in Hi range and about 80 psi when shifted to lo range.
Oops, my BAD :flag_of_truce:I confusing PTO clutch/brake with Hi/Lo clutch/brake.

For 2030 the spec (for warm oil 130°) is 140-160 for early w/indPTO and 125-135 for late models.

If your oil is not warm, that might be why you are getting the higher reading.
 

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I think repairing, or replacing the hollow shaft/tube/retainer is the key to repair. How did the clutch disks look in the hi-lo? If it is getting pressure to both at the same time, i would suspect you might have some overheated and warped disks. DId you pull the pistons out of the clutch packs and replace piston seals?
 

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Discussion Starter #18
80 psi is low indicating an internal leak. Actually IIRC system pressure should be 155-165 psi. I think oil to control hyd hi-lo travels through the 2 tubes highlighted in yellow in Z5's photo. l.
Thanks Tx Jim. My JD service manual clearly states 125-145 [email protected] 2100 RPM. The only time I run into a low pressure problem is at engine idle speed. Like I said, spec is at 2100 which says it passes. I am still getting 130 psi at 1350 rpm Truth be told, I really expected to see something in the Hi/Lo clutches housings when I tore it apart. I saw no signs of wear on any component, I examined all the steel tubes carefully as I know these can be known to crack or rub through. I have split many utility tractors in my 40+ years as a ag tech. More than I care to remember in fact. It just goes against my better judgement when I apply 150 PSI of shop air to the HI/Lo and PTO tubes under the shift cover and I can clearly hear each piston moving followed by no excessive air leaking in the housing, It makes me doubt my gut instincts. Truth is I had not replaced one o-ring or steel sealing ring. Terrible choice for a seasoned JD mechanic. (my bad)

I will split the tractor again this weekend and replace all the seals.
It just doesn't make sense to me.

Further testing concluded that the main hydraulic pump is reaching full system pressure and destroking. But this really isn't necessary because it is down stream from the oil flow/pressure required by the PTO and Hi/Lo circuits.

In your opinion what would happen if I were to eliminate any oil supply to the Hi/Lo. Will it still drive as it usually has one or the other clutch pack under pressure? My plan was to braze weld the end of the two small (and easily removable) hi/lo supply tubes. This can be done by popping them out and sealing them shut on my work bench. I have a feeling I will run into a lubrication problem.


Once again I appreciate everyones thoughts and suggestions, Thanks.
 

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Sorry for my mistake but I was relying on my aging memory & reading a correct tech manual as you did is much more reliable.:bigthumb: Just be happy that at least you're saving the expense of having dealer charging for guessing/diagnostics/repairs.
 

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Thanks Tx Jim. My JD service manual clearly states 125-145 [email protected] 2100 RPM. The only time I run into a low pressure problem is at engine idle speed. Like I said, spec is at 2100 which says it passes. I am still getting 130 psi at 1350 rpm Truth be told, I really expected to see something in the Hi/Lo clutches housings when I tore it apart. I saw no signs of wear on any component, I examined all the steel tubes carefully as I know these can be known to crack or rub through. I have split many utility tractors in my 40+ years as a ag tech. More than I care to remember in fact. It just goes against my better judgement when I apply 150 PSI of shop air to the HI/Lo and PTO tubes under the shift cover and I can clearly hear each piston moving followed by no excessive air leaking in the housing, It makes me doubt my gut instincts. Truth is I had not replaced one o-ring or steel sealing ring. Terrible choice for a seasoned JD mechanic. (my bad)

I will split the tractor again this weekend and replace all the seals.
It just doesn't make sense to me.

Further testing concluded that the main hydraulic pump is reaching full system pressure and destroking. But this really isn't necessary because it is down stream from the oil flow/pressure required by the PTO and Hi/Lo circuits.

In your opinion what would happen if I were to eliminate any oil supply to the Hi/Lo. Will it still drive as it usually has one or the other clutch pack under pressure? My plan was to braze weld the end of the two small (and easily removable) hi/lo supply tubes. This can be done by popping them out and sealing them shut on my work bench. I have a feeling I will run into a lubrication problem.


Once again I appreciate everyones thoughts and suggestions, Thanks.
I ASSUME you plan to eliminate oil supply to just ONE, HI OR LO, not both HI & LO.
In that case it should drive in which ever you pressurize, HI or LO.
UNLESS it is leaking pressure internally.

If you eliminate pressure to both HI & LO it should not drive.
 
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