GC2600 whining gone, then came back

Dmacleo · Jun 16, 2025

Dinico said:
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?

I don't remember for sure but think thats normal with just filter removal. will know for sure in few months when I do mine LOL

dicktill · Jun 16, 2025

Dinico said:
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.

Here's a photo of the PTO valve on the later model GC.

To answer your other question, a quart does seem like a lot of oil to drain out of the hydraulic filter, but I don't remember for sure.

Someone asked whether the PTO gears are always turning or not; I believe that they always turn when the PTO clutch is engaged, but they just rotate freely on their individual shafts. They only turn their respective output shafts when either the mid or rear PTO levers are engaged (i.e., I think that engaging the mid or rear PTO levers connects the gears to the shaft).

BTW, on your older GC, you can actually open up two windows on the left side of the transaxle and the shift forks for the two PTO's will come out. Don't know if you can get to them though with the transaxle inside the frame.

oldnslo · Jun 16, 2025

Dinico said:
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.

Well sounds like we can scratch another idea off the list.

Oil clearing up in 3 minutes kind of points towards a splash aeration but still doesn’t explain what changed to cause this.

Another potential silly question but was the fluid level different before you changed it? I.e. a little fuller like over sight glass?

dicktill · Jun 17, 2025

dicktill said:
<snip>

Someone asked whether the PTO gears are always turning or not; I believe that they always turn when the PTO clutch is engaged, but they just rotate freely on their individual shafts. They only turn their respective output shafts when either the mid or rear PTO levers are engaged (i.e., I think that engaging the mid or rear PTO levers connects the gears to the shaft).

<snip>

Duh. This is right, but this is wrong, and you shouldn't operate it that way! You should always engage either the mid or rear PTO gear first and then the PTO clutch. I'm sure you are doing this. So, the correct answer is that the gears are not always turning.