GC2600 whining gone, then came back

[Dinico]

Gears are not under pressure but turning at high speed in the oil which could cause foaming or some aeration from splash. If you run PTO with engine at idle does oil foam?

Is foaming different when running rear PTO vs mid PTO? Different gears at different speeds so may have different results.


Could be the PTO relief that is unstable causing vibrations in steel line. That could change with engine RPM, fluid temperature, etc.

Try driving at full speed for a period of time with PTO off to see if oil shows any signs of foam. Reason for this test is to see if gears from transaxle may also aerate oil at full travel speed operation.

I doubt hydraulic problem since only happens with PTO spinning.

How long does tractor have to sit before oil is clear?

Thanks for clarifying how the gears work and for the questions and suggestions.

Ran the tractor for about 2-3hours.
Borrowed a friend's zero turn, almost 2 weeks with tractor down, grass was tall. 1 ¹/2 acres. Mowed into rows raked into piles. Put forks on tractor and ratchet strapped a tarp onto forks. Daughter drove, I filled the tarp and bucket.

She drove back and forth dumping grass running full speed in fast gear. Checking sightglass often. Used the FEL. Not a single bubble. Always clear fluid. Checked temp couple of times and afterwards. Top temp at hydro filter was 135⁰F. Steel PTO line top temp was 125⁰F.

After grass, I watched the oil while she ran the mid-PTO with engine at 1500 rpm for 30 seconds. Fluid was all foam after 10 seconds. Looked the same as if at 3000 rpm. Takes about 2-3 minutes for oil to clear.

I put on the tiller Saturday. Ran it 15 seconds and oil was foam.

Steel line to PTO valve has never been hot to the touch. Really nothing on the transmission or hydraulics has ever been too hot to touch.

Not sure where the PTO relief is.

A shot in the dark. I see on the parts diagram:
#9 4264757M1 SCREW PLUG
#10 3758117M1 SCREW PLUG SEAL
Both where the steel line and the PTO valve connect to the hydraulic lift cover.

What are they? Are they under pressure?

 

[Dinico]

does the 2600 come with backhoe? think not,think was 2610 had it, but want to check.

Your correct. No backhoe on the 2600

 

[oldnslo]

Thanks for clarifying how the gears work and for the questions and suggestions.

Ran the tractor for about 2-3hours.
Borrowed a friend's zero turn, almost 2 weeks with tractor down, grass was tall. 1 ¹/2 acres. Mowed into rows raked into piles. Put forks on tractor and ratchet strapped a tarp onto forks. Daughter drove, I filled the tarp and bucket.

She drove back and forth dumping grass running full speed in fast gear. Checking sightglass often. Used the FEL. Not a single bubble. Always clear fluid. Checked temp couple of times and afterwards. Top temp at hydro filter was 135⁰F. Steel PTO line top temp was 125⁰F.

After grass, I watched the oil while she ran the mid-PTO with engine at 1500 rpm for 30 seconds. Fluid was all foam after 10 seconds. Looked the same as if at 3000 rpm. Takes about 2-3 minutes for oil to clear.

I put on the tiller Saturday. Ran it 15 seconds and oil was foam.

Steel line to PTO valve has never been hot to the touch. Really nothing on the transmission or hydraulics has ever been too hot to touch.

Not sure where the PTO relief is.

A shot in the dark. I see on the parts diagram:
#9 4264757M1 SCREW PLUG
#10 3758117M1 SCREW PLUG SEAL
Both where the steel line and the PTO valve connect to the hydraulic lift cover.

What are they? Are they under pressure?

I do not see what looks like the PTO relief or charge relief in either of those screen shots. I suspect that the PTO relief maybe part of the PTO valve assembly but am not certain of that.

Does the sound change when tractor engine is at idle? Does it change when oil is cold vs warm or at operating temperature?

125 - 135 degrees F sounds like a normal operating temperature and is nothing I would be concerned about.

Great job on running the tests and gathering all the information.

 

[dicktill]

<snip>

Not sure where the PTO relief is.

A shot in the dark. I see on the parts diagram:
#9 4264757M1 SCREW PLUG
#10 3758117M1 SCREW PLUG SEAL
Both where the steel line and the PTO valve connect to the hydraulic lift cover.

What are they? Are they under pressure?

The PTO relief valve is items #6-8 on the diagram.

Items #9-10 are fittings/seal. They are always under pressure but that should be limited to about 79psi by the PTO relief valve, which allows the fluid to return to the sump via the hydraulic oil filter.

This is fed from the return from the steering valve.

 

[oldnslo]

Dinico
I just went back and read this whole post again and it brought up some questions or thoughts.

I saw one of posts where you attached a screenshot of the PTO engagement valve and the line that resonates or is noisy. Looking at that valve is it lever operated rotary valve that engages the PTO? If yes is it possible that lever - valve assembly is not rotating fully? Reason for wondering is if it possibly rotate to a position where it bleeding off a little pilot flow which might aerate the oil when PTO is engaged.

I seriously doubt the foaming - aeration has anything to do with the suction line or filter since that is always in the loop when tractor is running.

If I understand correctly the foamy happens with either rear PTO or mid PTO so back to only common things arePTO gears spinning but would suspect different gears for rear vs mid and pressure going to PTO clutch so everything from engagement valve to clutch is suspect which leads back to original question on type of PTO engagement.

 

[Dmacleo]

Your correct. No backhoe on the 2600

I asked due to incorrect return line hookup can cause odd sight glass issues.
same if you had power beyond addon (rear hydro lines) and return hooked wrong.

 

[Dinico]

The PTO relief valve is items #6-8 on the diagram.

Items #9-10 are fittings/seal. They are always under pressure but that should be limited to about 79psi by the PTO relief valve, which allows the fluid to return to the sump via the hydraulic oil filter.

This is fed from the return from the steering valve.

I asked due to incorrect return line hookup can cause odd sight glass issues.
same if you had power beyond addon (rear hydro lines) and return hooked wrong.

Dinico
I just went back and read this whole post again and it brought up some questions or thoughts.

I saw one of posts where you attached a screenshot of the PTO engagement valve and the line that resonates or is noisy. Looking at that valve is it lever operated rotary valve that engages the PTO? If yes is it possible that lever - valve assembly is not rotating fully? Reason for wondering is if it possibly rotate to a position where it bleeding off a little pilot flow which might aerate the oil when PTO is engaged.

I seriously doubt the foaming - aeration has anything to do with the suction line or filter since that is always in the loop when tractor is running.

If I understand correctly the foamy happens with either rear PTO or mid PTO so back to only common things arePTO gears spinning but would suspect different gears for rear vs mid and pressure going to PTO clutch so everything from engagement valve to clutch is suspect which leads back to original question on type of PTO engagement.

Odd question. If I take the oil filter off first with the fill cap off, shouldn't more than a quart of fluid drain?

 

[Dinico]

Dinico
I just went back and read this whole post again and it brought up some questions or thoughts.

I saw one of posts where you attached a screenshot of the PTO engagement valve and the line that resonates or is noisy. Looking at that valve is it lever operated rotary valve that engages the PTO? If yes is it possible that lever - valve assembly is not rotating fully? Reason for wondering is if it possibly rotate to a position where it bleeding off a little pilot flow which might aerate the oil when PTO is engaged.

I seriously doubt the foaming - aeration has anything to do with the suction line or filter since that is always in the loop when tractor is running.

If I understand correctly the foamy happens with either rear PTO or mid PTO so back to only common things arePTO gears spinning but would suspect different gears for rear vs mid and pressure going to PTO clutch so everything from engagement valve to clutch is suspect which leads back to original question on type of PTO engagement.

The PTO engagement valve is lever operated. Seems to be a rotary valve. I'm looking at it now. I fully engaged the lever, then disconnected the arm that connects to it.

So when lever is fully engaged, the valve is open as far as it can. And when disengaged, the valve is closed as far as it can be.

I have looked for an actual picture of the valve, but couldn't find one.

 

[Dmacleo]

video it happening, including the frothing and level changes, upload to youtube and post link here so we can see/hear it.

 

[Dinico]

video it happening, including the frothing and level changes, upload to youtube and post link here so we can see/hear it.

Excellent idea, will do that.

I had decided to change out the fluid. Removed cap, and removed hydraulic filter first. Should more than a quart drain out?