Sickle bar mower, PTO, grinding noise

Julien

Member
I recently bought the neighbors' 1949 Farmall Cub. Unfortunately, the original owner is no longer with us, and no one knows how to operate any of the implents that came with it. I also have little to know knowledge of engines, machines and the like, although I am slowly learning. I finally got the sickle bar mower hooked up, filled up the hydraulic fluid, got it out of the shed, but when I engaged the PTO to get the mower running, it ran for about two seconds and then stopped working accompanied by a loud grinding noise coming from somewhere in the PTO/gear shifter area. I tried this several times with the same result. When setting up the mower, I didn't touch any of the mower parts as everything was already set up. I just had to hook it up to the Cub. Any thoughts as to what is keeping the mower from running? Thanks!
 
The PTO works by a sliding collar that joins the transmission input shaft to the PTO shaft. If that collar is not sliding far enough or the splines on the collar are worn or the PTO shaft has slid backward in the tractor, the sliding collar will not positively join the two shafts.

Working on the PTO is not a huge job, and can be done on a fully assembled tractor. Someone will come along with specific advice as to what to look for.
 
Hi,
The noise you described is caused by the clutch shaft splines that run the PTO, turning against the PTO clutch splines, when the PTO is not turning.
The splines in both parts could be worn, or other things can cause it. If you read everything in the post Jim B. posted above, that has info about what to look for.

The Cub owner's manual can help you learn about maintenance that the Cub needs.

The service manual in the link in the post above is more for use when the Cub needs repair.

Below is the 1949 Cub owner's manual. The experts on here recommend people read it. It has lots of info about operation, maintenance, and lubrication. There is a table of contents on page 1.
It shows how Cubs originally looked in it. The lube section begins on page 14.

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

It shows the electrical system that a 1949 Cub originally had.
Cubs made before mid 1964 originally had 6 volt, positive ground electrical systems.

The 10 weight motor oil mentioned in the manual for the Touch Control was changed later to Case IH Hy-Tran fluid. It is sold at Case IH dealers.
There are other brands, be sure it works with IH hydraulic systems before buying one.
The manual tells how to check and change the Touch Control fluid, and remove the air from the system.
Be sure to check the fluid with the arms in the rear, or down position, the manual says to also.

I would check or change all the oils before using the Cub. Using it with low oil in a gear housing can damage the parts in the housing.
There are 3 separate gear housings, with 3 separate oil levels to check, in the rear area of a Cub, the transmission, and 2 final drives.

The transmissions in Cubs commonly get water in them, from rain, or condensation inside the housing over time.

The air cleaner is an oil bath air cleaner. Dirt that is sucked in settles to the bottom of the oil cup. It should have clean, light motor oil in the oil cup to work right.

There is a search box at the top of the page, to the right of the Farmall Cub, you can find info in posts that have been made.

Below is the Cub 22 Mower owner's manual. It has lots of info about the mower.
You don't use the manual lift lever shown in the manual if the Cub has Touch Control.

There are manuals for other Cub implements at the top of the page at Cub Info, then go to Rudi's Manuals, then Cub Implement Manuals. :)

http://www.farmallcub.info/galleries/ci ... _Mower.asp
 
Hi all,
Thank you so much for the detailed and helpful responses! I did order a copy of the Cub manual, although I definitely need to be more proactive regarding the maintenance and oil. A local Farmall expert did give the tractor a once over before I obtained it, but I'm not sure if oils were changed or inspected. I also know that one of the repairs done was something having to do with peening something related the the PTO. The shaft perhaps? At the time I didn't know what a PTO was, and so the nature of the repair had little meaning to me. Not sure if that would indicate any problems to you more knowledgeable folks on here. I have been reading through the referenced thread regarding PTO disengagement. So, essentially I should follow all of the advice from that thread as far as diagnosing the specific problem? Checking the pin, the shaft, and the splines? In the case of worn splines, is it just a matter of ordering replacement parts? Thanks!
 
Julien":998maiow said:
I also know that one of the repairs done was something having to do with peening something related the the PTO. The shaft perhaps?
Hi,
They might have needed to stake the PTO shaft, at the bearing, to hold the shaft in position. I don't know if that was what they did.
The shaft can move to the rear if the staking is not holding.
Staking is shown in one of my posts.
IH staked them originally, when they made the Cubs.

Later the shafts were machined to use a snap ring at the bearing, instead of staking.

I think it was said in a post, but the problem could be that the PTO shaft has moved to the rear, because of the staking not holding. That would let it slip out of engaged.
Look at the PTO shaft right where it comes out of the housing, if it is shiny, or looks like the seal has run on it in the past, the shaft has probably moved to the rear, and needs staking in the right position.

Julien":998maiow said:
So, essentially I should follow all of the advice from that thread as far as diagnosing the specific problem? Checking the pin, the shaft, and the splines? In the case of worn splines, is it just a matter of ordering replacement parts? Thanks!
Yes, check everything in the posts. Parts that are worn should be replaced, so the PTO will work right.

The PTO clutch is easy to replace, if the splines are wornout, TM Tractor has a new one.

The other spline is at the rear of the long clutch shaft, which is one shaft up to the rear of the engine.
If the PTO splines are wornout on it, the Cub has to be split, at the transmission, like in one of the pics I posted in the post Jim B. posted, and the shaft replaced with a good shaft.
TM Tractor at the bottom of the page has those too.

If you don't want to do jobs like splitting the Cub, you could look for a good tractor repair shop to do the job, if it needs splitting and the clutch shaft replaced. :)
 
Hello and welcome to the forum.

The problem could be simpler than it seems. The shafts may be fine. The problem could be that the pin that rides in the PTO clutch groove wears down. The first picture in the attached thread by Bob shows the part l'm talking about. If it is worn it won't move the clutch forward enough to engage properly. If that is the case and it has been happening for a while, the splines on the inside of the clutch could be worn also (it's a softer metal than the drive shaft).
You will still need to take it apart (the PTO) to verify, but it may not be as dire as replacing shafts, staking, or splitting the tractor. Pull the PTO and post some pictures of what you find. That will help us help you because we can see what it looks like.

Good luck
Hutch
 
Greetings,
Thanks so much for all of the feedback! I hope these pictures are sufficient. Apparently my hands are just small enough to reach into the transmission box to grab that pin. I'm not sure what to look for on the pin, as to whether or not that is worn, but some of the splines on the PTO shaft certainly do look worn away to me. Is it now a matter of buying a replacement shaft? Thanks!
 

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Hi, it appears it's worn enough to cause your problem. In the middle picture it looks like a flat spot on the pin. Replacements are available from TM or Hamilton Bob's. Some people have been successful repairing it using a drill bit shaft of the appropriate size. (Forum search will reveal many discussions with this subject)

Good luck!
 
The shaft looks pretty ugly but clean it up good, maybe on a wire wheel and give us a better look at it. The lever pin is definitely worn out. You need to take a good look at the clutch (engagement collar) and the splines on the back end of the transmission clutch shaft. If they still look decent you might get by addressing the parts shown. Also, make sure the pto pilot bushing is present and in decent shape. Show us pics. of all these things.
 
Hi,
If you replace the PTO shaft and bearing, like Dale showed above, you may need to have the bearing pressed on the shaft, sometimes they fit tight.

You didn't say if you looked to see if the PTO shaft has moved to the rear, that can cause the problem your Cub has. You could post a pic of where the shaft comes out of the housing if you want.

The PTO pilot bushing is mentioned in the specifications on page 6A-2 of the service manual, telling it's size. There isn't a pic, I guess.

Below are listings at TM Tractor.
The 1st is the PTO shifter lever and shaft, the small pin that runs in the PTO clutch slot has to be round, so it fills the slot. Yours has a worn flat place on it. That can let the PTO splines slip out of engaged.
I would replace it.
Or if you know someone that can weld and repair things. you can do what dgrapes59 said above.
People have replaced the pin with a piece the right size and length of a hardened drill bit, so it will last and not wear out soon.
The pin has to be welded well, so it won't fall out. The pin can break gears if it falls out of the shifter lever, and gets in turning gears.
You can see the pin at the bottom of each pic in the listing, it is round.

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

Below is the PTO pilot bushing, it goes in the rear end of the clutch shaft. The small front end of the PTO shaft goes in the bushing.
If you are using the same PTO shaft, I would sand the end of the shaft with fine sandpaper so it is shiny and smooth. I would put some grease in the pilot bushing, and on the end of the shaft, as you put the PTO in the Cub.

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

Below is the PTO clutch. The splines may be worn on yours, but I don't know without seeing it.

http://www.tmtractor.com/new/pt/449fp.htm

Below is TM Tractor's page of PTO parts, you can look at the pics of how the parts should look.
The bottom 2 rows are not for the PTO, they are for an extra cost attachment.

http://www.tmtractor.com/new/pt/pt_001newparts.htm

Read Jim B.'s link that he posted above again, and the service manual PTO section that I posted there.
The PTO pilot bushing is shown in my last pic in Jim B.'s link above.
The pic above it, looking in the rear of the housing shows where it is, at the front of where the PTO shaft would be.
People have said on here that their PTO pilot bushing was nearly worn away, or gone. If yours is that way, you might not see the bushing in the hole. Use a light to look for the bushing.
Good luck. :)
 
Hello,
The shaft was very firm in the housing. There was no play when I would try to pull on it. I have attached a picture, not sure if it shows what needs to be shown. If not, I can take another one with a close up of where the shaft meets the housing.
IMG_1702.JPG
Is it possible that the bushing fell off into the transmission case when I removed the PTO? Otherwise, I guess it is worn off, and I need a new one.
I cleaned up the splines as best as I could to get a better look at the situation.
IMG_1716.JPG
IMG_1717.JPG
IMG_1719.JPG
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Looking inside the transmission... Not sure if the attached picture shows anything of value, but it was the best picture I could get.
IMG_1710.JPG
Thanks for your help!
Julien
 
I think your photos show evidence of the set screw in the collar being placed on the wrong spline and being tightened down to the point of not being able to move as designed. The last photo appears to show the bushing in place, but maybe not fully seated. Hard to tell with all the dirty gear oil.
 
I think the last photo shows the bushing missing, not too uncommon, just hope the bore of the isn’t too worn for a new bushing to fit. I’ve had to sometimes make a custom fit bushing, including the last 2 I’ve worked on. The alternative is to replace the clutch shaft. I agree with Don’s assessment of the pto shaft, someone has buggered it up, pretty good, somehow. If the collar fits and slides properly, it still may be usable, though. Lightly tap the pto shaft, first rearward, then forward and see if you get any movement. Movement would indicate a failure of the staking Dale referred to.
 
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