PTO / Gear grinding

M

marshall

Well-known member
While mowing with my sickle bar the pulley on the PTO fell off. I got a new cotter pin and put it back on. I also added some more oil to the gear case and felt that this would improve things. Instead, now I've got a bigger problem

When I use the PTO touch-control to engage the sickle and have my foot all the way down on the clutch the grinding is bad. When the touch control is fully in the rear position and I let off the clutch, the PTO spins a few rotations and then makes a grinding sound, stops spinning, and pushes the touch control forward to where it jams in the in-between state between the rear and front positions. Way worse than it ever was.

I will admit that it did grind a bit when going from a dead stop to 1rst gear. But I don't know about clutches and gears and this just seemed like a project that would be beyond me.

Can anyone tell me what I might have done in my installation of the pulley to foul things up so badly? Did I overtighten the PTO belt? Is there more to it than putting that pulley on the PTO, sticking a cotter pin through and (attempting) to get the bolt that clamps the pulley tight? I wouldn't say that the belt drum tight now. It's still got some play, and I can hand-turn the pulley. Here's a video (with sound of grinding) of what I'm talking about (you might have to download to play it - sorry)
https://drive.google.com/file/d/1PHA0fsfFu_0NahNn_haC6nBBd_yOynd0/view?usp=sharing
 
Sounds like you’ll be going in to do some repair. The pto clutch collar is not fully engaging. There are quite a few posts on here about repairing this problem. Also, when you depress clutch and attempt to engage pto, you should let the driveshaft stop spinning so that it will engage without grinding
 
Hi,
If the PTO grinds when engaged, and slips out of engagement, it probably has worn parts inside the housing, and needs repair.
It is the PTO lever, not the Touch Control. The Touch Control is the hydraulic system on a Cub.

No, putting the pulley on the rear of the PTO shaft probably has nothing to do with the PTO not working.
It has probably had worn parts in it for years, I'm not sure when you bought the Cub.

The PTO assembly has to come out the rear of the transmission housing to check it, and repair it.

A common thing that happens to them is the pin that holds it in engaged wears, and then it can slip out of engaged, like you are describing.

Below is a listing at TM Tractor for the part, it is the pin in the lower part of each pic that wears.

http://www.tmtractor.com/new/pt/317fp.htm

If you don't want to take it apart, you could have a shop that repairs tractors do it.

The right parts have to be replaced, if they are worn, so it will work right.

The transmission housing should be filled only to the oil level plug hole low on the left side of the trans. It holds 3 1/2 Pints of oil to fill it to there.
It wouldn't hurt anything to add more, but it might run out the oil seals where the brakes are.

Below is a pic of the trans housing after removing the PTO and rear cover.
The PTO is run by the shaft in the upper part of the pic. :)
 

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if its grinding going in to 1st gear make sure the clutch is adjusted correctly so the clutch is fully released before putting in to gear
 
It has probably had worn parts in it for years, I'm not sure when you bought the Cub.
Click to expand...
The clutch pedal has had a lot of play in it these last few years. Probably 4-5 inches before I feel it engaging.

I bought it about 9 years ago and the gear grinding and PTO belt slippage has been developing over the last 5 years so I've known that eventually this was going to be a problem.

This one feels like a pretty long-term project for me since I can only grab an hour of time here and there so every now and then it'll probably pop to the top of the list of posts and then lay quiet for periods of time. Hope y'all will hang with me as I'm bound to have more questions. I'll follow your instructions and see what else I can find in previous posts. If I find problems and a fix I'll try to document the repair project with pictures so that in the end maybe it'll be useful to the next person who hits this.
 
I also lower the throttle with the clutch in when changing gears or engaging the PTO to reduce /stop grinding and put it back up before I release the clutch.
 
marshall":a1c6z8hz said:
The clutch pedal has had a lot of play in it these last few years. Probably 4-5 inches before I feel it engaging.
Click to expand...
Hi,
The clutch pedal free play is supposed to be 1", measured at the top surface where you put your foot.
The free play is measured with the engine off, it is the movement of the pedal from up against the platform, until you feel the pedal contact something solid.

I would measure the free play to be sure what it is now, and then change it if needed.
The clutch probably can't release right with as much free play as you said.
It runs out of motion before going far enough ahead to release right.

It is easy to adjust the free play. You just loosen 1 bolt at the base of the pedal, and move the pedal in the slot.

Below is a page from the 1950 Cub owner's manual showing how to adjust the free play.
The is a pic of the clutch lower on the page.

http://farmallcub.com/rudi_cub/www.clea ... e%2040.jpg

If you are getting a metal to metal sound when you push the clutch pedal fully down, when the engine is running, the throwout bearing or it's holder are hitting the pressure plate. Don't push the pedal down far enough for the noise to happen, it will damage the parts.
If you are getting the noise, the pressure plate fingers are probably too low, and need raising up.
But there could be some other problem. The graphite material of the throwout bearing could be worn down.

I don't know if you have greased the throwout bearing, like the operator's manual says, it helps it to have less friction with the pressure plate fingers, and wear less.
There is a grease fitting on the throwout bearing.
They say on here to use cheap grease, so the oil in the grease absorbs into the graphite material.
I wipe a small amount of grease on the front surface of the bearing also.

You get to the grease fitting, and can look at the clutch through the hand hole under the clutch housing, use a good light to see in the hole.
It is helpful if the tractor is in a building, so you don't have to look up at the bright sky.
The pressure plate finger height can be set through the hand hole, there is info in the How To section about it.
Look at the throwout bearing, the graphite material sticks out of a new bearing 5/16". The material can get worn down from use.
Clutches are not bad just because they are old, some old ones are still good.
It isn't easy to see in the hole with a Cub 22 Mower under the Cub.

There should be return springs on all 3 pedals under the platform, to hold the pedals up to the platform. The clutch pedal would always go ahead until the throwout bearing rubbed on the pressure plate fingers without the pedal return spring.

Below is the Cub and LoBoy service manual, it has lots of info.
I would read section 6A, the PTO section, and see what the PTO is.
There is a contents beginning on page 1 of most sections, it makes it easier to use online.
Disregard the info for the Belt Pulley Attachment, if you don't have one. It isn't the pulley that runs the Cub 22 Mower.

http://farmallcub.com/rudi_cub/www.clea ... index.html

Below is a pic of a new throwout bearing, you can see the graphite material sticks out 5/16". :)
 

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OK. I think I misunderstood the free-play. Mine was set roughly like diagram. From where the pedal contacts the floor plate it moves forward freely about 2-3/4". It then moves forward about another 1" at which time there is resistance and then the pedal moves not very far (~1/2") until there is metal-to-metal contact. When the engine is running, there is no grinding when I depress the clutch all the way.

I'd tried adjusting so there is less free movement just to see, but do get the grinding sound once the clutch moves beyond its free-play range.

Now that I see that lubrication port, I'll give it a few pumps of grease.

I think I need to come at things from the PTO end. I'm going to take off the PTO housing and transmission housing and see what I find in there. Hoping I can find this worn pin you're talking about. When I've got it off, I'll take pictures and post them so I can get some input about the condition of things.
 
The pin that can wear is at the right-hand end of the part in the photo below.

c4134s.jpg

Photo courtesy TM Tractor Parts
 
Got the transmission housing off. Here's what I observe (actually studying photos is better than looking at it in life).
As you see there's a bolt holding that wheel on the PTO shaft and the bolt has been filed down a good bit. In the last shot I can see an area on that circular plate around the PTO shaft that the plate is ground down (from the 9 O'Clock - 1 o'clock positions) probably by this bolt. So that's probably the grinding I've been hearing when I engage the PTO? I see that the lever / pin looks OK to me. PTO shaft has a little wear from where that wheel sits on it but they still mesh together snugly. I can send more pictures but I'm not seeing anything inside those transmission gears that looks bad. In fact the gears all look very good and non-worn.

IMG_0841.JPG
IMG_0833.JPG
IMG_0831.JPG
IMG_0826.JPG
 
The pin is not OK. It has a flat worn in it that shouldn’t be there. From my observation, you will need to replace the PTO shaft, the clutch collar and the lever.
 
Where you have the bolt, there should be a set screw that is aligned with a flat on the shaft. It should be tight enough to keep the collar from falling off, but loose enough that the collar can slide forward and back. I agree with Don about replacing those parts now.
 
Hi,
Thanks for the pictures.

Below is the Cub and LoBoy service manual, it has lots of info.
I would read the PTO section, section 6A, before working on the PTO.
There is info in section 6A for the Belt Pulley Attachment, disregard it if you don't have it.
It isn't the pulley for the Cub 22 Mower.
There is a contents beginning on page 1 of most sections, that makes it easier to use online.

http://farmallcub.com/rudi_cub/www.clea ... index.html

This manual was made in the 1970's so it has newer, 12 volt electrical system info.

You could have looked in the transmission oil filler hole with a light, and seen the pin that runs in the PTO clutch slot.
You need to look in the hole to put the PTO back in again, so you can see if the pin is in the slot.

The PTO Lever and Shaft, it is called at TM Tractor, with the pin on it Definitely Needs Replacing, it is worn flat on 1 side. That is what commonly on Cubs can make the PTO slip out of engaged.
It is in the upper part of your first pic.
Small amounts of wear on some parts can make them not work right.

Below is the listing for it at TM Tractor, you can see in each pic the pin is round, that fills the whole slot in the PTO clutch, so it can't slip out of engaged.

http://www.tmtractor.com/new/pt/317fp.htm

There is a PTO pilot bushing in the end of the shaft that runs the PTO.
It looks like it is wornout and gone in your pic, I can't see it too well in your pic.
It is another common thing that wears out on Cubs.
People on here have said the PTO wouldn't shift into engaged right when the bushing was worn.
Below is a listing for it at TM Tractor.
If you have a dial caliper, measure the size of the hole in the end of the shaft, and the front end of the PTO shaft.
There should only be a few thousandths difference in the sizes.

http://www.tmtractor.com/new/pt/752fp.htm

The front end of the PTO shaft is supposed to be smooth to run in the PTO pilot bushing, yours needs smoothing with fine sandpaper, if you don't replace the shaft.
Below is a listing for a new PTO shaft. You can look at the pic.

http://www.tmtractor.com/new/pt/514fp.htm

Below is a pic from TM Tractor of the rear of the clutch shaft, showing the PTO pilot bushing. :)
 

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Hi,
It sounds like your engine clutch needs the height of the 3 pressure plate finger adjusted.
They are probably too low.
On the one I have seen with the problem, the grinding sound is what happens when the fingers are too low, and you set the free play at 1".

This is a separate project than the PTO repair I wrote above. :)
 
Dale Finch":3c4v241q said:
In the first photo above looking inside the differential housing, I don't recognize the "ring" around the clutch shaft. (The back side of a sealed bearing?)
Click to expand...
Hi,
That is the older trans shaft rear bearing in his pic than your 1955 Cubs have. It is the rear shield over the bearing that you see in the pic.
They are a roller bearing with a bigger OD than Cubs serial number 180614 and above have.
The newer bearing is a needle bearing. :)
 
Thanks, Glen! I knew I hadn't seen one like that! As you said, all my cubs are "newer"!! :lol:

But it still looks like something was rubbing it...maybe that messed up PTO clutch collar was fixed in place with that screw to keep the PTO permanently engaged, but had been fixed too far forward.
 
Where you have the bolt, there should be a set screw that is aligned with a flat on the shaft. It should be tight enough to keep the collar from falling off, but loose enough that the collar can slide forward and back. I agree with Don about replacing those parts now.
Click to expand...

I'm figuring on just replacing a lot of parts now that its opened up and I'll be incurring shipping costs.

I've added the PTO shaft, lever pin, gasket, and collar to my TM tractor cart.
But I'm not seeing the set screw or the pilot bushing on the TM tractor site. If they're there, can someone point me at them. O/w maybe I can buy these from Steiner or somewhere else (links, please)?

Are there other relatively inexpensive things like bearings I should replace while I'm at it?

I'd love to get this back together and actually be able to use it before the summer is over.

Glen, I'll follow your instructions for adjusting the clutch once this PTO is rebuilt.

Thanks all!
 
The set screw will come with the shifter collar. If you can remove the bolt and reuse yours, it's a standard size. TM has the bushing under PTO, part # PT 752.
 
Based on Glens reply to Dale identifying that bearing with the grind marks on it I'm wondering if I'll be able to get it out and replace it. Here's what I'm guessing is the right part: http://www.tmtractor.com/new/pt/155fp.htm

Let me know how I'd get it out. Pry from rear with a flathead screwdriver?


I just want to be sure I understand the set screw vs bolt issue. On mine there's a ground down bolt that happened because it was too close to the bearing and needs to be further back on the shaft. My understanding is that it should instead be a SCREW which I would assume has a much lower profile and would not grind on the bearing. I assume the location of the collar on the shaft also depends on getting it to line up so that the lever pin fits into its slot correctly.
 
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