Late 4020 PS pto noise

[Scott 730]

Is there any noise that would normally be heard on a power shift PTO that is engaged with nothing hooked to the shaft?
Never noticed the noise until after I had cut 18a of rye this summer with my PT combine. It is not a "scary" sound like grinding, etc. It's hard to describe. It starts when you begin to feather the PTO into engagement. Maybe a "whine" would be a good description, but it is not extremely loud, nor high pitched. Thank you.

 

[wore out]

I would start by examining the filters and the sump screen (and the area beneath it) for metal filings.

It won't PROVE anything, but finding a significant amount of filings would certainly be more worrisome than if just a few/almost none!

It's about all you can do without a major teardown to examine LOTS of bearings, IMHO.

Also, you could use a length of hose as a stethoscope to possibly narrow down the area the sound is coming from.

 

[M w J]

That is totally normal the sound you hear while PTO putting in gear is oil flow threw valve
while activating PowerShift PTO once it is engaged the noise stops .

 

[Scott 730]

Thank you, but my noise remains when the PTO is fully engaged. The noise begins as you feather the lever forward.

PS. If you say some noise from the valve is normal as the pto is being engaged, would there be a big external oil leak if the valve was bad?? Just thinking out loud. I could see how my noise could possibly be from hydraulics, not mechanical.

This post was edited by Scott 730 on 12/18/2021 at 05:41 pm.

 

[wore out]

(quoted from post at 18:35:55 12/18/21) Thank you, but my noise remains when the PTO is fully engaged. The noise begins as you feather the lever forward.

PS. If you say some noise from the valve is normal as the pto is being engaged, would there be a big external oil leak if the valve was bad?? Just thinking out loud. I could see how my noise could possibly be from hydraulics, not mechanical.

This post was edited by Scott 730 on 12/18/2021 at 05:41 pm.

The 4020 PS PTO valve gets oil from the transmission pump, regulated at about 140 to 160 psi, so not the potential for a big internal leak/noise as if it were part of the high pressure hydraulic system.

 

[Scott 730]

So if the pto valve did have a leak, would it be an internal leak, or would you see oil coming out somewhere?

 

[wore out]

(quoted from post at 20:58:36 12/18/21) So if the pto valve did have a leak, would it be an internal leak, or would you see oil coming out somewhere?

Powershift PTO valve is "internal", inside the aluminum valvebody on the side of the tractor, under the platform, beneath your left foot, along with the foot "clutch" valve.

You could check the PTO operating pressure at the test port in that valve body, looking for a steady 140 to 160 psi, IIRC.

 

[Scott 730]

Thank you for the explanation.

 

[Scott 730]

OK had the 4020 running today and did a bit more troubleshooting. When engaging the pto I can feel a vibration, I guess I would call it, in the inching pedal. When holding my hand on the valve body at the inching pedal, I can feel it with my hand. The sound seems to be coming from the valve area also. It is hard to hear the pto noise over the engine at higher rpm, but I don't think the noise changes with rpm. The noise does get quieter as I am raising the loader. I think I have a hydraulic issue of some sort in that valve. I would maybe now say the noise is similar to a hydraulic pump that is starving for oil. What do you experts think??? Thank you, and Merry Christmas!!!!!

 

[wore out]

(quoted from post at 11:58:30 12/24/21) OK had the 4020 running today and did a bit more troubleshooting. When engaging the pto I can feel a vibration, I guess I would call it, in the inching pedal. When holding my hand on the valve body at the inching pedal, I can feel it with my hand. The sound seems to be coming from the valve area also. It is hard to hear the pto noise over the engine at higher rpm, but I don't think the noise changes with rpm. The noise does get quieter as I am raising the loader. I think I have a hydraulic issue of some sort in that valve. I would maybe now say the noise is similar to a hydraulic pump that is starving for oil. What do you experts think??? Thank you, and Merry Christmas!!!!!

The FIRST thing would be to change the hydraulic and transmission filters and check and clean the sump suction screen, then have a look at clutch operating pressure.

There's a pump at the front of the transmission that surrounds the input shaft (just like a typical automotive hydraulic transmission) that supplies the power shift transmission and the PTO clutch and brake with operating oil, once those needs are met the remaining flow supplies the main hydraulic pump.