GC2600 whining gone, then came back

   / GC2600 whining gone, then came back #1  

Dinico

Member
Joined
Jun 6, 2025
Messages
29
Tractor
Massey Ferguson GC2600
Long story short.

Tractor 650 hours. I bought with 400 hours. Maintained, scheduled maintenance since I owned it, garage kept, only repairs: new starter, two hydro lines on FEL.

My tractor has a constant whine. I determined it resonates from the steel hydro line that connects from the transmission to the PTO engage lever.

Doing other maintenance, decide to replace hydro filter with OEM filter even though doesn't need changed for another 150 hour. Suction filter was clean, cut open hydro filter and it was clean.

At start up, the whining was gone completely gone. Tractor ran, mowed, and sounded great. Reverse was even quicker and stronger. Ran better then ever. Daughter mows more than me and agreed.

Next day, on start-up, the whine is back. Like it never left, or I was driving someone else's tractor the night before. Night and day difference. Then I find that the hydraulic fluid now becomes foam when using MMmower.

Foam settles out in eyeglass after a few minutes.

ORings on suction filter looked good, not seeing any leaks.

Any advice?
 
   / GC2600 whining gone, then came back #2  
Just throwing some ideas into this. Did you notice any foaming of the oil at the beginning of all this or just since the noise went away and came back? Do you notice oil foaming if you don't use the mower? Is the oil level overfull?
 
   / GC2600 whining gone, then came back
  • Thread Starter
#3  
Never had any foaming issues prior.

1st time I've ever seen foaming was after the noise went away then came back.

Only foams when using the mower. I've taken the deck off checked for any leaks. Slightly tightened the suction filter and hydro filter. There was one drop of fresh oil on the hydro filter even though it was hand tight plus a half turn. Put deck back on, still foamy. Suction filter o-rings were properly aligned.

Disconnected the FEL lines and reconnected.

Oil level is slightly above halfway sitting in garage with FEL and 3pt down.

I'm at a loss. Can the hydro filter cause aeration?
 
   / GC2600 whining gone, then came back #4  
Long story short.

Tractor 650 hours. I bought with 400 hours. Maintained, scheduled maintenance since I owned it, garage kept, only repairs: new starter, two hydro lines on FEL.

My tractor has a constant whine. I determined it resonates from the steel hydro line that connects from the transmission to the PTO engage lever.

Doing other maintenance, decide to replace hydro filter with OEM filter even though doesn't need changed for another 150 hour. Suction filter was clean, cut open hydro filter and it was clean.

At start up, the whining was gone completely gone. Tractor ran, mowed, and sounded great. Reverse was even quicker and stronger. Ran better then ever. Daughter mows more than me and agreed.

Next day, on start-up, the whine is back. Like it never left, or I was driving someone else's tractor the night before. Night and day difference. Then I find that the hydraulic fluid now becomes foam when using MMmower.

Foam settles out in eyeglass after a few minutes.

ORings on suction filter looked good, not seeing any leaks.

Any advice?
Just throwing out a weird idea to see if it sticks: perhaps it has something to do with the PTO clutch; perhaps it is leaking. The PTO clutch is a series of wet plates that are engaged hydraulically.

In this screen print from the later service manual, the clutch pack is just to the left (forward) of the arrows from the 8 balloon. Those arrows are pointing to two O-rings that run on the shaft. Further aft, behind the gear and the bearing are two more O-rings (balloon 2). Hydraulic oil is injected through the passageway by balloon 1 into the hollow shaft between the aft O-rings, through the shaft, and exits the shaft between the forward O-rings.

Massey Ferguson GC PTO clutch pack & seals 1.jpg

Two more screen prints from the later parts manual. The PTO clutch pack is #45, the forward O-rings are #46, the shaft is #41, and the aft O-rings are #42.

Massey Ferguson GC PTO clutch pack & seals 2.jpgMassey Ferguson GC PTO clutch pack & seals 3.jpg


Try "pseudo-mowing": driving it around with the mower raised and the PTO not engaged and see if it still whines and foams.
 
   / GC2600 whining gone, then came back
  • Thread Starter
#5  
Just throwing out a weird idea to see if it sticks: perhaps it has something to do with the PTO clutch; perhaps it is leaking. The PTO clutch is a series of wet plates that are engaged hydraulically.

In this screen print from the later service manual, the clutch pack is just to the left (forward) of the arrows from the 8 balloon. Those arrows are pointing to two O-rings that run on the shaft. Further aft, behind the gear and the bearing are two more O-rings (balloon 2). Hydraulic oil is injected through the passageway by balloon 1 into the hollow shaft between the aft O-rings, through the shaft, and exits the shaft between the forward O-rings.

View attachment 3595347

Two more screen prints from the later parts manual. The PTO clutch pack is #45, the forward O-rings are #46, the shaft is #41, and the aft O-rings are #42.

View attachment 3595348View attachment 3595349


Try "pseudo-mowing": driving it around with the mower raised and the PTO not engaged and see if it still whines and foams.
Hope it's not the PTO clutch. That is above my pay grade.

I did some "pseudo-mowing" as you calles it. Moved some bucket loads of compost to the garden, mower raised, and PTO not engaged. Still whines, but did not foam.
 
   / GC2600 whining gone, then came back #6  
foaming could be from deck vibration I suppose.
I have a whine with deck engaged, I have cap on tractor and it amplifies the noise. noise is mostly from deck itself, airflow/gear noise/etc.
I don't have foaming though.
there is ALWAYS a little hydro noise even on brand new GC tractors, thats normal.
run it until it breaks. you'll drive yourself insane chasing noises.
 
   / GC2600 whining gone, then came back
  • Thread Starter
#7  
Good morning all,

I'm thinking the best course of action is to retrace or redo what caused the hydraulic fluid foaming. It wasn't foaming before I changed the filter. New one is AGCO filter 4265229M92 Made in Japan. That shouldnt be the issue.

The O-rings on the suction filter are properly seated. If I tighten it any more, it will break. Suction tube hose- I did tighten the clamps a turn for good measure, but that was after the foaming started.

Cold fluid level was slightly above the middle sitting in level garage with FEL down and 3pt down.

That leaves the obvious. The fluid. I am using the NAPA Starfire Premium HTF. Says it's M1145, Permatran III and 821 XL, anti-wear, foam suppression, VI is 141, GL-4, Group II Base oil. Same brand, I was using along with a NAPA cross-refernced filter.

So my plan:
1.Drain the fluid that's in it. It's junk.
2. Use the oil that was in it before the change to kind of flush out what junk oil remains. (I had drained it into a clean pan, and put into a clean bucket. Nothing was wrong with the oil when I changed it. I had read that an OEM filter may stop my whining. Which it did for about 2 hours. Then next day whine was back along with foam.)
3. I will cycle it and drain.
4. I'll do this and report back if it is foaming.


Questions are: Will this procedure help to get most of the foamy oil out so I don't contaminate new oil? Do I need to do this multiple times to get all junk oil out?

Should I replace the brand new filter I just put on with a new one?

And what fluid? The closest dealer to get Permatran 821 XL is 70 miles one way. Is there something better? At this point, I want what is best. Kinda answered my own question on that one. 🤷

Thanks for any suggestions or comments.
 
   / GC2600 whining gone, then came back
  • Thread Starter
#8  
foaming could be from deck vibration I suppose.
I have a whine with deck engaged, I have cap on tractor and it amplifies the noise. noise is mostly from deck itself, airflow/gear noise/etc.
I don't have foaming though.
there is ALWAYS a little hydro noise even on brand new GC tractors, thats normal.
run it until it breaks. you'll drive yourself insane chasing noises.
You are right about the chasing noises. Would be glad for just the whine and no foam at this point.
 
   / GC2600 whining gone, then came back
  • Thread Starter
#9  
OK. I drained the foamy oil. Emptied out filter. Put back in the oil that was previously in it. Let it warm up a but before cycling. Then cycled the FEL and 3pt lift.

No foam in eyeglass while it's idling.

Should I put the deck back on to cycle the PTO?
Doing it without a load seems not good.

And after cycling the FEL and 3pt, they are both down now, the eyeglass barely shows any fluid.

Top it off?
 

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