PTO engagement

[Rambus]

I have a 49 Cub and having problem getting the pto to engage, it grinds and wont completely engage. Any help please

[Dale Finch]

A few things might be wrong, but most are fairly straightforward fixes...and not too involved.

First, does the transmission engage without grinding?

A common problem is the little pin (#15 below) on the PTO shifter gets worn (due to other possible problems) and does not push the PTO clutch (#14) far enough forward to couple the PTO shaft to the main drive shaft.


Another very common problem is if you have the older-style PTO shaft with the staked bearing (# 10 & 11), the staking can get worn down enough that the bearing moves forward on the shaft, which is the same as the shaft moving back, increasing the gap between the PTO shaft and the drive shaft, again uncoupling the 2.
Here is a post I made regarding the PTO rebuild:
http://farmallcub.com/phpBB2/viewtopic.php?f=1&t=100075

You should be able to pull the PTO by removing ONLY the upper bolts (7 I believe) holding it in, then simply pulling it to the rear...no need to drain the transmission gear oil. You may need to jiggle the PTO shifter to disengage it from the clutch. You can shine a light in through the transmission filler plug on top of the transmission to see the shifter, and determine if it is worn flat instead of round.

To remove the shifter, you unbolt it from the transmission cover, remove the cotter pin, take it apart and the shifter lever, itself, is removed from inside the differential housing.

[tst]

remove the oil fill plug on top of the transmission, look through to the right side while moving pto lever you can see the collar that engages the pto
the pin in the middle of the groove should be nice and round that moves it, if it is sloppy in that groove or the pin is flat on one side you found the problem

[Rambus]

With the clutch in and engine running I engage the PTO lever to where it stops and when I let the clutch out it grinds and tries to run PTO but pushes the lever back out. If I try and hold it in it grinds and pushes hard to disengage
Hope I'm explaining it right.

[Crimson Tim]

Yup. Sounds like one of the above mentioned issues. Worn pin or moved bearing. If it has been a problem for a while, it may have rounded over the ends of the splines on the PTO clutch, too, requiring replacement.

Has any transmission work been done recently? There’s a bearing in the front of the transmission that can be put in backwards which allows movement in the transmission shaft and the same failure to engage symptoms.

[Rambus]

No trans work that I know of. Have had tractor 5-6 years and have not used the PTO until now, I bought a 22 Sickle mower and am in process of hooking it up and running it before I remove it to paint this spring
Thanks so much
Randy

[Rambus]

Ok this what I find in the PTO
Took plug out and can see the shaft and collar don't see anything unusual but the collar didn't seem to move towards the trans all the way. Took a bar and moved it a little towards the trans and it popped into place. Could run the PTO just fine. When I took PTO out of gear it was okay but I couldn't get it back engaged again without using the rod pushing it back into gear.
Question is there any adjustments I can make
Or do I need to pull the PTO out.

[Crimson Tim]

That the collar doesn’t move far enough doesn’t really tell us much. Pretty much all of the possibilities mentioned manifest in the same result, it’s just a question of which part is out of position causing the problem.

It might be as simple as adjusting plate 17 from the diagram above. That’s the plate with the keyhole in it that the PTO lever passes through.

The important part from what you just checked, though, is did you verify the pin that pushes the collar (PTO clutch) forward and back is not worn?

[Rambus]

Unable to see the pin that I can tell
should I just pull the PTO out then. I moved the plate 17 so it could move more but didn't seem to make a difference. When I moved the collar with the bar it would stay in place and when moved forward it would take it out of gear, but again it would not reengage

[Dale Finch]

As Crimson Tim said, you need to see if that pin is round. The extra bit you pushed the collar/clutch forward, could be the amount of wear on that pin. Get a brighter light and look again.

Actually, no matter what it is, you WILL need to pull the PTO. That way you will know for sure. If the pin looks good, then it's likely the shaft movement. You'll need a new gasket, and might as well replace that PTO seal...available from NAPA, etc.

As said, you don't need to drain the transmission, but if it hasn't been done in a while, why not?!

[Dale Finch]

One thing I will mention... I have 4 tractors with belly mowers, and almost all, when you go to engage the PTO, will often need you to EVER SO SLIGHTLY let the main clutch out WHILE putting back pressure on the PTO shifter lever. As soon as the two shaft splines line up, the clutch moves on forward for the coupling.

So my question where are, are you just pulling the shifter back, when the main shaft may still be turning? And if you are, indeed, waiting for the main drive shaft to stop turning, have you tried finessing it as mentioned in my first paragraph?

[Nelson 634]

I have a similar problem with one of my tractors. I have repaired it numerous times. As has been stated look in the fill hole while standing on the left side of the tractor. Look to the far right side of the transmission. Your looking for the leaver with the very short pin. The pin should be round. Now having said that, it's hard to see in there. Do yourself a favor. Get yourself a LED penlight with a flexible end on it. You can find them at numerous retail outlets including Amazon and Harbor Freight for $10.00 and up. One final point CHECK the shaft forward for damage to the spline. Don't do what I did and replace with out checking. I replaced that PTO lever twice and I still don't have a PTO that works. The PTO will pop out of gear repeatedly. The worn spline teeth will destroy that little pin on the PTO lever.

[Rambus]

Thanks everyone, I have tried finessd the clutch but it kicks it back out grinding sound.
I can move the lever and can see the collar move some but not enough to engage. With the tractor off I can take a small bar and thru the oil fill hole slide the collar forward and it will engage and stay there and I can run the tractor with the PTO working, but if I move the lever to disengage it will do so but can't reengage it.
Again thanks will try and see what's going on.

[dgrapes59]

FYI, here's what the mentioned pin on the lever should NOT look like

Good luck

[Rambus]

Yes it looks somewhat like that as best as I can tell. How do I change that?
Thanks
Randy