TC-40A PTO Problem

[mundamanu]

Hello all,

Recently when operating the PTO I have been hearing a high pitched grinding sound -- it sounds a lot like someone running a stick very very quickly over a washboard.

The sound is intermittent, of variable duration -- lasting from a tenth of a second to one second, maybe two at the longest -- and is usually related to operating the tractor on a slope, with the tractor pitched down and to the left side (facing forward). Sometimes the sound will pop up frequently when pitched like this, sometimes not for ten minutes. The sound very occasionally happens with the tractor pitched down and to the other side. It has only happened once or twice and of very short duration with the tractor going uphill or flat.

Fluid levels are normal and hydraulic filter changed within the last few hundred hours. There are 2300 hours on the tractor.

Any ideas?

 

[jinman]

I think there are lots of possibilities, but the first things I would check are the two universal joints on the PTO driveline to the cutter and maybe the protective cover. All of this sounds like something related more to the cutter than the tractor. I'm guessing that you are pulling a cutter because of your description of moving across a slope. You might remove the cutter and see if the noise will show up with nothing on the PTO. Keep the PTO engaged and just spinning as you drive across various terrain.

 

[mundamanu]

I checked to see if it would make the noise with nothing attached to the PTO and it does, although not as frequently and not as loudly.

The sound is definitely coming from inside the tractor, and it sounds like grinding gears that are rotating very fast. But, again, it is intermittent, of variable duration, usually only happens on a downward slope to the left (facing forward). Could something have come loose from its housing in the PTO clutch/transmission/whatever?

Further thoughts?

 

[jinman]

Okay, it is isolated to the tractor. It sounds like a shaft bearing is failing, maybe the output bearing of the PTO stub at the rear of the tractor. Since you have not said that the PTO clutch is slipping, I doubt that is the problem, but you never know. Your PTO driveshaft is the center of two concentric shafts coming out of the snout of the transmission. The PTO shaft is driven by the engine no matter what the status of the clutch. That's what makes it a fully independent PTO. Does your pressing on the clutch have any effect on the noise? I would expect it would not make any difference because when you are moving and have the clutch off, the PTO driveline and the transmission driveline rotate at the same speed. Since you say it is inside the case, this just sounds like a bearing to me. When gears make noise, they make it constantly in my experience. That's why I think this is bearing noise.

 

[JC-jetro]

I agree with Jim's statement as the only thing coupling pto final shaft and the input shaft is your wet clutch. There no meshing of gear by demand. pto input shaft is splined to crankshaft/flywheel permanently. the noise might come from pto clutch not grabbing good or some shaft bearing along the pto system.

JC,

 

[Jerry/MT]

Okay, it is isolated to the tractor. It sounds like a shaft bearing is failing, maybe the output bearing of the PTO stub at the rear of the tractor. Since you have not said that the PTO clutch is slipping, I doubt that is the problem, but you never know. Your PTO driveshaft is the center of two concentric shafts coming out of the snout of the transmission. The PTO shaft is driven by the engine no matter what the status of the clutch. That's what makes it a fully independent PTO. Does your pressing on the clutch have any effect on the noise? I would expect it would not make any difference because when you are moving and have the clutch off, the PTO driveline and the transmission driveline rotate at the same speed. Since you say it is inside the case, this just sounds like a bearing to me. When gears make noise, they make it constantly in my experience. That's why I think this is bearing noise.

I don't have the specifics of this tractor model at hand so i'll make some general comments.

When you step on the drive clutch with the pto engaged, the pto shaft remains turning while the driveline shaft stops. IF there are any bearings between the two shafts, there is differential speed between the stopped shaft and the pto shaft. So IF there is a bearing there that was failing then, I'd suspect it would howl under that condition. Somewhere down stream of the tranny, I believe, is the reduction gearing for the pto shaft and there are some bearings there that can make noise with the pto operating. There is also the output shaft bearing , the last one on the shaft.

When I operate my rotary cutter, the intermittent squeaks I hear do not comefrom the tractor. They come from the shaft safety shield or the pin connections on the three point as they react out sideloads.

 

[Floyd b]

I checked to see if it would make the noise with nothing attached to the PTO and it does, although not as frequently and not as loudly.

The sound is definitely coming from inside the tractor, and it sounds like grinding gears that are rotating very fast. But, again, it is intermittent, of variable duration, usually only happens on a downward slope to the left (facing forward). Could something have come loose from its housing in the PTO clutch/transmission/whatever?

Further thoughts?

I have a problem with the PTO clicking sound when the clutch is disengaged and the mower deck is slowly stopping . The sound is click click click as the PTO is coming to a stop . Is this something to be concerned about?

 

[jinman]

Floyd, a comparison of your TT75A and the TC40A is not something you can do. Your tractor may have a built in over-running clutch that works like a ratchet and clicks normally.

 

[Floyd b]

Thank you

Floyd