PTO...how does this work?

[agford4x4]

Im curious about the PTO 'modulator' on the DX series tractors. My dad has a MF240 that i used as a kid, and you had a double clutch that you had to fully engage to get the pto in gear, then after that you had two choices, engine speed pto, or ground speed.

My DX you only have engine speed, but you don't have to engage the clutch. So, how does this system work? Apparantly, its not 'hard geared' like my old man's.

Are all the new case tractors like this? Is this type going to cause problems with shearpins when i start up the pto for the shredder??

 

[thcri]

Im curious about the PTO 'modulator' on the DX series tractors.

PTO Modulator?? I guess I have never heard of that. I have a New Holland TC29D and my PTO with a Hydro Transmission you do have to put the clutch in to engage it? And it will vary speed by RPM's not ground speed. With the Hydro I am able to change directions, change speed without changing PTO.
I am not aware of the system you are talking about? Are you sure you can engage your PTO without putting in the clutch??


murph

 

[jbrumberg]

agford4X4:

I agree with thcri. I would not engage the PTO without depressing the clutch. Jay

 

[FULLPULL]

If your talkin about the dx55 .It should be the same as my tc55da it has a independent pto a hydraulic clutch pak.You can engage the pto slowly to start your implement this is done with your pto clutch lever .On my tc55 you dont have to use the clutch or inching pedal to start the pto.You adjust the pto rpm with the engine speed 540 pto is 2475 rpm engine speed once gear.Ground speed doesn't matter for pto speed on this system.There also should be a extra light on instrument panel to indicate 540 pto rpm when the speed is reached at 2475 engine rpm.Hope this helped.

 

[agford4x4]

yes, but i was curious about how it works. I can slowly start the pto and then engage it all the way. Is this pto operated with a fluid instead of gears or what? I envision a torque converter type thing with fluid fins. Im curious because another poster noted shearing pins because the independant on his tractor was either ON or OFF and it tended to start abruptly, whereas my independant im able to very slowly start the pto.

 

[FULLPULL]

My tc series tend's to slowly engage if wanted.We had a old 4000 with independent pto that was in or out of pto no inbetween's .I guess the pto has a clutch pak operated with hydraulic presure.This system or close to it has been used for a few year's. If you want to see a break down look at nh website under part's then look up tc55da.They have the whole tractor microfish style there.I dont think it is all gear's like the older tractor's.

 

[FULLPULL]

I guess what i tried to say is that it's not a all gear drivin pto say like a 8n ford.No converter like a full hydro transmission.The clutch pak is fluid compressed.

 

[jinman]

yes, but i was curious about how it works. I can slowly start the pto and then engage it all the way. Is this pto operated with a fluid instead of gears or what? I envision a torque converter type thing with fluid fins. Im curious because another poster noted shearing pins because the independant on his tractor was either ON or OFF and it tended to start abruptly, whereas my independant im able to very slowly start the pto.

Please continue to start your PTO slowly with the engine at low RPM. Before you disengage the PTO, when you have a shredder attached, lower the engine RPM first and then disengage the PTO. Your PTO will last much longer that way. My tractor was purchased early in 2001 and has never had a PTO problem because I follow these rules.

Here is how your PTO works:

The PTO is engaged by a hydraulically operated clutch/brake assembly. It is truly an independent PTO. When you move the lever, fluid is routed to the PTO clutch to engage it. It takes about .8 gpm flow to that circuit. The clutch pads also work as a brake when you release pressure to stop the PTO. Rotation will stop in just a few of seconds even with a shredder.

Many older tractors would allow the shredder to continue to spin freely (like an overrun clutch does). The braking action of the PTO clutch on the DXs is really challenged when a large cutter is attached. By slowing the engine and the speed of the PTO, you will save the PTO clutch. You will also save shear bolts by slowly engaging your PTO. My TC45D (like the DX45) will snap a shearbolt in a heartbeat if I forget and suddenly engage the PTO.

If you have one of the DX35/40/45 tractors, you don't have a regular transmission clutch pedal. You have no other way to feather the engagement of the PTO except the yellow lever on your left fender console. I have used mine so much that I know the exact position where the lever will engage when the tractor is cold and when it warms up. You just learn these things after repeated use.

This last weekend, I was cutting some dry weeds and grass around some small trees. Suddenly, I noticed a different sound and looked back to see the cutter was not moving and the shearpin was just fine. My heart skipped a beat for a second until I realized a tree limb had pushed my PTO lever to OFF. Whew! I lowered the RPMs, engaged the PTO, and continued.

 

[Wanting to fix this]

Hey I think i know what you are talking about. i hav 47 farmall b and it had the mechanical pto that when i let out the clutch to abruptly it would shear off the pin that held the yoke to the pto output. It got so bad after a while that i began carrying a box of pins to replace them again. My tractor stopped runing about 5 years ago... problay for good measure because when the shaft to the shredder would fall of of the pto, it would swing and extend in a huge circle. I cauld have lost by head by now.

 

[jinman]

Hey I think i know what you are talking about. i hav 47 farmall b and it had the mechanical pto that when i let out the clutch to abruptly it would shear off the pin that held the yoke to the pto output. It got so bad after a while that i began carrying a box of pins to replace them again. My tractor stopped runing about 5 years ago... problay for good measure because when the shaft to the shredder would fall of of the pto, it would swing and extend in a huge circle. I cauld have lost by head by now.

The "headless tractor man" ...what a great halloween costume.