TO-20 Clutch Not Releasing

To20Chris · Jun 24, 2015

Hello all. It's been years since I posted here, but I have a problem with my TO-20 that has me perplexed and I thought perhaps someone would have encountered it before. Basically the clutch does not like to release - it will, but only after I hold the pedal down for a while and/or jamb on the brakes to jar it loose. I have it filled with Ford tractor gear oil from TSC, and it is a bit over filled. I'd been told years ago that was the correct fluid, but I'm wondering if that is really correct? I believe it to be a wet clutch, and I cannot come up with anything else that would cause this other than the fluid basically gluing the clutch surfaces together.

Thanks in advance!

DJ54 · Jun 25, 2015

The TO-20 has a dry clutch.

How much free travel do you have in the pedal..?? It should be about 1" from the top, before you feel the clutch release bearing make contact with the pressure plate fingers.

If you've had the tractor for a while, and it started doing this lately, do you notice it may take less pressure to depress the clutch pedal..??

It could be it simply needs adjusting, or if the pedal feels a bit spongy, it could be a broken/weak spring in the pressure plate. A couple other possibilities are, that if the clutch was slipped quite a bit, and gotten hot, they can warp, and drag. Also, if the rear main seal on the engine is leaking, it can soak the clutch disc, causing it to stick a bit. But you usually get some slippage along with the last one. One other possibility is that the pilot bearing is worn enough, it's letting the input shaft drop enough to bind the clutch disc.

If it would happen to be that the clutch pedal needs adjusted, I've attached a photo of the bolt clap you need to loosen, to adjust the free play.

To20Chris · Jun 25, 2015

DJ54 said:
The TO-20 has a dry clutch.

How much free travel do you have in the pedal..?? It should be about 1" from the top, before you feel the clutch release bearing make contact with the pressure plate fingers.

If you've had the tractor for a while, and it started doing this lately, do you notice it may take less pressure to depress the clutch pedal..??

It could be it simply needs adjusting, or if the pedal feels a bit spongy, it could be a broken/weak spring in the pressure plate. A couple other possibilities are, that if the clutch was slipped quite a bit, and gotten hot, they can warp, and drag. Also, if the rear main seal on the engine is leaking, it can soak the clutch disc, causing it to stick a bit. But you usually get some slippage along with the last one. One other possibility is that the pilot bearing is worn enough, it's letting the input shaft drop enough to bind the clutch disc.

If it would happen to be that the clutch pedal needs adjusted, I've attached a photo of the bolt clap you need to loosen, to adjust the free play.
View attachment 430870

Thank you for the information and the correction - apparently the thing that's all wet is me, not the clutch! Of course this changes the analysis completely.

When the clutch sticks, it is like it's fully engaged - it continues to pull a brush hog in decently tall grass uphill in 3rd gear for at least 5sec until it pops loose. When it is released there is no hint of drag. It's exactly like when a clutch gets rusted fast, except it happens over and over - but the clutch must be left engaged for a minute or two first. It takes jamming on the brakes hard to pop it loose fast (not too safe...).

The clutch feel is normal, and I have tried adjusting it.

At this point the only thing I can think of that could cause this is some sort of contamination on the clutch surfaces that makes it stick, although the pilot bearing idea is something I need to consider too. It seems to depend on the time it is engaged.

DJ54 · Jun 25, 2015

There is an inspection plate on the bottom of the clutch housing. You could remove it, and with a trouble light, or a good bright flash light have a look. Probably best to do it in a dark building, or wait until later in the evening, if you can't get it in where it is darker. Should be able to see in there a lot better.

mrosian · Jul 5, 2015

I have a Massey 1035 that does something much the same. After sitting for a little while the clutch sticks like your saying. Unfortunatly this time it is not letting go. Ive tried braking and it will stall the engine. The PTO clutch is stuck also and when I opened that plate to have a look I found some flaked type rusted metal along with the adjustment within specs. Is it possible water has been getting in there? I dont know as Ive only had this machine a year or so.
I dont have any adjustment on pedal left so I suspect worn out whatever to do with that. I guess its strange due to no slip. I wonder how hard to tear it down and replace all inside. Any info or links to web with tips etc would be helpfull and appreciated.
If the clutch surfaces are sticking together for some cotamination reason is it possible to spray brake cleaner or some type of solvent in through the inspection plate opening to clean off, or is this just a worn out clutch assembly and bite the bullet and change it out with new? Thanks for any help or ideas.

To20Chris · Jul 13, 2015

mrosian said:
I have a Massey 1035 that does something much the same. After sitting for a little while the clutch sticks like your saying. Unfortunatly this time it is not letting go. Ive tried braking and it will stall the engine. The PTO clutch is stuck also and when I opened that plate to have a look I found some flaked type rusted metal along with the adjustment within specs. Is it possible water has been getting in there? I dont know as Ive only had this machine a year or so.
I dont have any adjustment on pedal left so I suspect worn out whatever to do with that. I guess its strange due to no slip. I wonder how hard to tear it down and replace all inside. Any info or links to web with tips etc would be helpfull and appreciated.
If the clutch surfaces are sticking together for some cotamination reason is it possible to spray brake cleaner or some type of solvent in through the inspection plate opening to clean off, or is this just a worn out clutch assembly and bite the bullet and change it out with new? Thanks for any help or ideas.

I have not had time to look into this further, but it sounds like your symptoms are a little different - mine will stick again while in use if I let the clutch engaged for a few minutes, such as after making a few rounds while brush hogging a field. It may be possible that yours is rusting fast while sitting.

WilliamTO-35 · Aug 5, 2015

I had a sticking clutch with my Ferguson TO-35 . The pedal and linkage adjustments outlined above should be tried first.
My sticking problem was apparently caused by engine oil getting on the clutch disk . I solved the problem by removing the bellhousing inspection plate, and spraying a lot of lacquer thinner onto the clutch disk . That removed the oil, and the problem has not reappeared for about 10 years now. If I had to do it again, I'd use mineral spirits , since lacquer thinner
is very volatile and flammable. I've also heard of cleaning the clutch using a CO2 fire extinguisher . A water soluble grease remover might also work, and be less hazardous. Brake cleaner would also probably work nicely, and not leave any residue. Use one that does not contain any chlorinated solvents. Wear a respirator with activated carbon filters.