TC35D PTO won't engage

tractorblue · Oct 3, 2010

Last few times mowing the PTO would slow down, intermittant with load, now will not engage at all. The PTO lever has no adjustment (welded from factory) I've spayed WD-40 where the arm enters casing. (I've by passed the PTO switch) I'm suspecting PTO relay or PTO clutch although not sure where they are located? Not sure if related but the 3pt lift is non fuctional as well, this seems to have statred long before PTO issues. Throw in another twist. The adjustment valve for lift (below seat) seems stripped out, its got slop that moves in and out. How screwed am I?

jinman · Oct 4, 2010

Wow! Did you save up a whole list of problems so you could get a quantity discount.

:laughing:

I don't mean to make light of your problems, but you obviously have several issues that need to be addressed one at a time:

1. 3PH does not lift/operate
2. PTO does not operate
3. 3PH drop rate knob is wobbly/loose

I first need to know if you have a FEL? Does it work okay? If it is working okay, then your hydraulic pump is fine. I also need to know if your PTO lever was ever stiff and if it could have been bent while trying to get the PTO to engage? I'm going to look up some threads and come back to add links to this post for some things to check. If you can answer the questions above, it really would help me.

EDIT: I've added a photo and an illustration below. There is a plug inside your FEL joystick valve that may be open. To get to it, you have to remove the hex-head cover on the top of your joystick valve. In the diagram below, it is circled in green, and in the photo with the cowling removed, it is also circled in green. Below this cover is an allen head screw that can get loose and allow hydraulic fluid to bypass the circuit to your 3PH and return to the reservoir. You need to reinstall the allen head and tighten it down to make your 3PH work. That might also effect your PTO engagement, but I have my doubts that it will be the complete cure. If you look at the picture below, you can see the 3PH drop speed knob is crooked in the hole. I had the whole operator platform raised and the knob disconnected. I think your knob has just come loose and may need to be reinstalled. To get to it, you have to remove the seat, but you may have to do that to troubleshoot your PTO problem too, so removing the seat is going to be something I will ask you to do after we find out what is wrong with your 3PH.

tractorblue · Oct 4, 2010

Ha,, I did'nt even mention starting problems < I did find faulty switch and replaced so it starts fine now.

I do not have front end loader.
any help is greatly appreciated!

tractorblue · Oct 4, 2010

No FEL
The PTO lever has never been bent.
Thanks for any feedback!

jinman · Oct 5, 2010

tractorblue said:
No FEL
The PTO lever has never been bent.
Thanks for any feedback!

It sounds like you have some major hydraulic problems. Either your pump is not pumping properly or your diverter and relief valve are gummed up. Since it takes hydraulic power to engage the PTO properly, this is not looking good. Here is what I want you to check. Look up under the operator platform on the right side of your tractor for an assy with hydraulic lines attached like the illustration below. This will be below your HST pedal levers and attached to the transmission case. This assy is call the System Relief and Diverter.

In the attachment below the illustration at the top is the diverter valve. Callout #9 points to a slotted shaft. This shaft should be in exactly the position shown if you do not have a FEL. If you have a FEL, it would be rotated 90 degrees counterclockwise, but since you said, "No FEL," your tractor should look exactly like the one on the attachment.

In the illustration below, callouts #2 and #3 point to the line that goes to your PTO clutch. The diverter on the front of the block sends 0.8 gpm flow to the PTO clutch when you operate the PTO lever. This flow/pressure is what holds the PTO engaged. Since you've lost PTO function, that tells me that you are probably not getting flow.

On the bottom of the diverter valve block there is a system relief valve. If a piece of trash is holding this valve open, you will not have hydraulic pressure. It is shown at the bottom of the page, callout #13. Items 8-12 make up the relief valve. If you remove this valve to see if it is stuck, you MUST be sure to reinstall the pieces exactly as they came out, especially the shims, item #10. You must also be careful not to damage the o-ring seals or you will have to get new ones.

If these things don't reveal a problem, then I would say you need the help of your dealer's shop. The hydraulic pump is probably not pumping. If you don't have gages to check the pressure, you'll be easter egging the problem. The one thing you might look for is to check the rubber boot on the input line to your hydraulic pump to make sure it is tight. That boot is near the diverter valve and held in place by hose clamps.

tractorblue · Oct 5, 2010

Jim,

Really good of you to provide all the tips and schematics. I was really hoping to pull the relief valve and find a gummed up port, but all looked good. Cleaned her up and reinstalled. Still no hydraulics. I did tightened the hose clamps, although they was no sign of leaks. I'm getting to know this machine more than I ever dreamed. Up until now I've been very pleased with it for the last 826 hrs (10 yrs). I guess its like me, getting up in years (52) and having to pay more attention to maintaining health. I'm really starting to question the hydraulic flow valve (located under the drivers seat. As I mentioned in my original post) it has some how stripped out over the last 6 months and thats when I started noticing the 3 pt lift was really finicky about going up and down. Now the valve is obviously stripped and disengaged, you can feel about a half inch slop moving it in and out. when turning it you dont get a sence that anything is turning. I can definately attribute the 3pt hydraulics being affectted but I have no idea if it also affects the PTO? Thanks for the advise, Maybe I need to check the hydraulic pump or zero in on the flow valve?

jinman · Oct 6, 2010

T-blue, I don't want you to "chase a ghost" on this problem. I don't see how the drop rate needle valve could have anything to do with this problem since it only affects how fast fluid leaves the lift cylinder when the HPL valve is placed in the lower position. If the valve was wide open, it would not affect the raising of your 3PH. There may be something wrong with it, but I am almost 99.9% sure it has nothing whatsoever to do with your current problem beyond maybe shedding a piece of metal that has clogged an orifice or interfering with normal hydraulic flow. If you want to remove your seat, you can easily see the valve and also the PTO engagement valve to verify how they look from close-up. As I remember, the seat just unbolts easily from the operator platform, and it has an opening below it as you can see in the previous photo I posted.

I'm attaching a diagram of your complete hydraulic system. Item 12 is the drop rate valve. Item 5 is the relief/diverter valve, but since you don't have a loader, the diverter valve is turned to allow fluid to go straight thru to the HPL. Item 8 is a rear remote valve which I'm pretty sure you don't have either, so your system is the simplest configuration with the least chance of anything going wrong. I think you need a pump pressure/flow test. There's a good chance that your hydraulic pump has sheared off it's input drive gear and may not be putting out any fluid whatsoever. That would account for your PTO and 3PH not working. Just not sure. . . .