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Cub 129 PTO clutch problems

Posted: Mon Apr 08, 2013 12:21 pm
by ppopp1618
Hi,
New here and to servicing my 129. Guy I bought it from said he already rebuilt the PTO clutch but I am not sure. So i have no idea how this thing is suppose to function when it is working correctly. What it is doing is the deck is staying engaged even when I pull the handle back. It makes it real hard to start with a load on it. II was working fine for two seasons. I have the older clutch set up, the one with out the shoe assembly. I notice their is no wear button, looks like it sheared off in the hole or the guy never put one on. How does this thing work, the wear button contacts the thrust button and pushes in the pressure spring? That in turn pushes the clutch disk against the clutch plate? Is the clutch disk (that looks like a gear with teeth) always engaged in that thing that looks like an old jello mold? I really apologize for not having all the terminology down. I would like to asses what the issue is but not sure how to determine what the issue is. Is it the pressure spring, maybe the thing is not adjusted correctly, I see you need a special gauge to set these thing up. The fact that I am missing the wear button the issue? I assume not because I am assuming the clutch is normally not engaged and will go back to that position when the handle is pulled back. I did manage to get the clutch assemble off the shaft. Really don't want to buy a whole new unit for $350-$400.

Any help on where to begin or a video describing how it functions or a written description would be much appreciated. I sue this as my primary tool to cut my grass and its going to be that time of year soon.

Thanks,

Phil

Re: Cub 129 PTO clutch problems

Posted: Mon Apr 08, 2013 3:44 pm
by BigMike
First off Phil,
Welcome!

Yes,the missing button is an issue but it sounds to me like the clutch needs adjusted with the proper gauge.You can get a kit and go completely through the clutch AND you will have the gauge.

Re: Cub 129 PTO clutch problems

Posted: Mon Apr 08, 2013 4:10 pm
by ppopp1618
Thanks for responding BigMike,
Is their any way of figuring out what part needs replacement with out getting the whole kit? Does a rebuild kit come with instructions on how to put it back together. I do not have a shop manual for the unit. So does the pulley assembly move in and out to engage and disengage or is it just the friction pad move to engage the plate?

Thanks,

Phil

Re: Cub 129 PTO clutch problems

Posted: Tue Apr 09, 2013 8:11 am
by BigMike
I do not believe you can buy individual parts.I think the kit consists of a "cogged" friction plate,three anti rattle springs,the infamous gauge and instruction(I hope :lol: ).The pulley is fixed on the end of the crank.The clutch is released by the button pressing on the center of the three fingered spring.

Re: Cub 129 PTO clutch problems

Posted: Tue Apr 09, 2013 10:43 am
by Klapatta
If the clutch was engaged while the button was missing most likely there is damage to the clutch fork on the button side.
The hole will be burred over and attempting to install a new button will result in it snapping off. It's best to send a taper reamer through the hole on the pressure side to remove the burr. In this case there could also be damage to any or all of the clutch fingers from the fork striking the fingers, inspect them.
TypeTaperTHandle.gif
TypeTaperTHandle.gif (3.34 KiB) Viewed 6852 times
I have seen a few that the hole was actually loose too from the button spinning. In that case a dab of epoxy will retain it ;)

Re: Cub 129 PTO clutch problems

Posted: Tue Apr 09, 2013 11:35 am
by ppopp1618
Thanks for commenting I really appreciate it.

clutch fork, not sure what part that is. I included a parts diagram of the PTO set up. Do you mean the pressure spring(# 15 in the diagram)? and when you refer to button do you mean the thrust button(# 14 in the diagram)? sorry I am asking for clarification of part names I am new to clutches in general. So the thrust button should be tight in the pressure spring, it is. So does pushing on that button make the pressure spring flex in and out?

Thanks for all your help.

Phil

Re: Cub 129 PTO clutch problems

Posted: Tue Apr 09, 2013 12:43 pm
by Klapatta
Not item 15. If the fiber button (item 13) is missing there could be possible burr damage to the fork assembly (item 12) as well as the clutch fingers (item 25)
It sounds as though item 13 is missing or broken off. If so, that would also not permit proper clutch engagement.

Re: Cub 129 PTO clutch problems

Posted: Tue Apr 09, 2013 1:57 pm
by ppopp1618
Ok,Now I got it. I don't think the fingers got messed up but will check. I think the previous owner may have just had a bolt in their and used the head as the ware button. I will order a new one. If no damage to the existing thrust button or fingers, the thing should still not be engaged when the clutch fork is not touching the thrust button, correct?

Thanks for explaining.

Phil

Re: Cub 129 PTO clutch problems

Posted: Tue Apr 09, 2013 2:07 pm
by Paulf
Phillip, when #13 pushes on #14 it takes the pressure off of #'s 19, 20 and 21 and the clutch is disengaged. Item #20 will spin with the engine and #'s 19 and 21 will not rotate. With no contact between #13 and #14 the clutch is engaged, there's pressure between #'s 19, 20 and 21 and everything rotates with the engine.

Hope this helps.

Re: Cub 129 PTO clutch problems

Posted: Tue Apr 09, 2013 2:18 pm
by Paulf
Phillip, I forgot to mention that you can purchase #'s 13 and 14 separately without purchasing the entire clutch repair kit. I've had good luck with the fiber replacements for #13 but a lot of people replace those with brass buttons. You can purchase them from several different vendors. I've found lots of PTO's where the PO has replaced #13 with a bolt. The problem is that usually wears #14 to a point. It should be a nice "domed" shaped button. If it isn't it will wear out those fiber buttons in a hurry. To replace #14 you'll need a gage to properly set the spring tension when you reassemble the clutch. I don't know if you can purchase those, but I'm sure several people on this site would be willing to help you out there.

Re: Cub 129 PTO clutch problems

Posted: Tue Apr 09, 2013 2:53 pm
by Klapatta
Thank you, Paul. Well done :)
My thinking about the brass thrust buttons is that I will never use another again.
This one with less than 20 hours run time ground down item 14 to nothing left to show.
I'll stick with the stock ones.
DSCN2970.JPG
I think they retain sand and dirt and become a lap that grinds away at the steel thrust button, at least that's been my experience.
Others have had good luck with them but not me. :lol:

Re: Cub 129 PTO clutch problems

Posted: Wed Apr 10, 2013 7:48 pm
by ksanders
I've made a whole bunch of those brass pto buttons and as long as they're made with 360 Brass they hold up well from what I've seen. Some of my neighbors have some that have never been an issue, all of mine on my tractors don't wear themselves or the thrust button, and I'm yet to have a complaint on one I've sold.
My built 73 is actually my tilling, sometimes mowing on occasion, snowblowing, and even used for the chipper/ shredder which probably puts more wear on the button than a year's worth of mowing every time it's disengaged as it winds itself down. That wear button is the only one I've seen with any wear, and its just a small start of wear on the brass button over probably 150+ hours and a lot of disengaging and rubbing on the thrust button. I've never seen one wear a thrust button and personally am done breaking $5 fiber buttons while being extremely careful in installing them.
The brass buttons also give me the option of making one custom to fit into a screwed up rockshaft that someone didn't put a new button in or thinner ones for something like my Original with front pto that doesn't have room for a normal size fiber button. Heck, I've even used on when the thrust button was chewed into by a bad rockshaft some to avoid taking it all apart. I don't expect one of those to last forever under those conditions but doesn't just destroy it like it would a fiber one.

Other's experiences may be different and I certainly don't mean to argue but the brass buttons I've made and use in all of mine have been a blessing and a big relief of stress that fiber buttons have always caused me and saved me from some costly and timely work on related parts around it when I didn't have the time.

Re: Cub 129 PTO clutch problems

Posted: Thu Apr 18, 2013 12:16 pm
by ppopp1618
Thanks all who responded. The clutch works great now that I have a ware button in place. Great site, glad to know I am not the only one who loves keeping great old machines running.

Thanks,

Phil