125 flywheel or drive cup help needed
 

The dowel in the front of my drive shaft broke the other day. I was looking all over for a 1/4" x 1 1/2" dowel.My lousy local Cub dealer had nothing and didn't even know if he could get one, and neither of my local hardware stores had anything. I bought a grade 8 1/4" bolt and went home to see what I could do. I found what looks like the remains of a brass door hinge pin under the tractor where it stopped driving (luckily just outside and up hill of the barn door) and some more of it om the pan under the drive shaft.
http://i115.photobucket.com/albums/n...5/DSC06558.jpg
The shaft and cup are worn enough that I was able to get the 1/4" bolt ib there and put a nut on it.
http://i115.photobucket.com/albums/n...5/DSC06562.jpg
The tractor drives OK now but I know that there are some parts that have to be replaced. The drive cup and flywheel have a bunch of play in them. Click on the picture for a video. http://i115.photobucket.com/albums/n...h_MOV06559.jpg

What parts do I need here and how involved a job is this gonna be? I figure that I will need the drive plate, flywheel drive, maybe a flywheel, and drive shaft? I am not clear on how I would get to these parts either. Split the tractor? Remove the engine? Please let me know what I an getting into here.
Thanks

I don't like using the bolt to fix a problem that will only get worse...The Drive pin and cup are available at one of our sponsors.

Should be able to get to the broken parts by unbolting the motor from the frame. You may have enough slack in your fuel line, wiring harness, and choke/throttle cable to slide the engine forward about 3/4-1" to get the drive shaft to drop out of the pin cup. You will need to remove the mesh cover that attaches to the frame that covers this area to make accessing the offending parts easier. If anything is holding you up from sliding the engine forward, just unhook those items. If you want to remove the entire drive shaft you will have remove the engine and unbolt it at the hydro pump from underneath the tractor, remove 2 bolts from the flex disk.

Mc master carr has the harden pins. I might have extras. I'll look for ya. Send me your addy and if I have 1 I'll send it to you.
Mike

I've replaced some of what your refuring to on my 125 and 123, it's not that bad. I found it easier to just pull the engine. Undo the throttle and choke cable at the carb. Remove the wire to the coil, and the one's to the S.G.
Next thing I did was to disconect the PTO rod at the turnbuckle followed by the four engine bolts and it makes it easier to take the muffler out too. Oh, and take the two bolts out that hold the regulator to the front to get it out of the way.
Pull the engine forward to disconect it from the driveshaft and pull it out. You may have to wiggle it a little, but it will pop out.
And I too could get you the the pins if need be, my dealer has them on hand, as well as all the parts you would need.
I went to another cub dealer in another town, and they had nothing on hand for these old tractors, everything had to be ordered, sure glad I've got a good dealer near by with most parts on the shelf.
Good luck, it's not really to bad once you get into it.

Wow, and I though mine 129 was bad - that's a lot o play there!

Is there an upgrade for him that would help eliminate the problem in the future?

I can't remember where I saw this, but I read that the WF models can use the dual flex-coupling driveshaft out of the Quietline model. Could that also be adapted for a NF model?

I don't think anyone mentioned this, but if you continue to use your worn cup, you will continue to break pins. You need to replace the worn cup.

AJ

Call Rich at Patton Acres. I believe he has new steel drive cups, driveshafts, with the pins. You could get the pins from Mcmaster carr.

Thanks for the help. I guess I'll have to slide the engine forward and see what I need. My local Cub dealer sucks! They were a JD dealer until only a few years ago. They have just about nothing in stock and now they want to charge me for the shipping to them! Whatever I need, I will have to buy elsewhere. I hate the idea of getting into something like this and not being able to get parts quickly and easily. I'd rather not have the tractor in pieces for weeks waiting for parts.

As we all knew it would, the 1/4" bolt either broke or fell out today. This time at was across the street in an empty lot that I have been clearing. I put another bolt in there so I could drive it home. Once back in the barn, I decided that I would take some time to look a little deeper into the problem. I couldn't sllide the engine forward enough to get the drive shaft out so I went ahead and took the hood and grill off, disconnected the choke and throttle cables, and the wire harness and lifted the engine out.
http://i115.photobucket.com/albums/n...0617111546.jpg
Once I got it all out I found that the bolt that tightens the drive cup to the flywheel had come loose! Only the pressure if the drives haft and the pin were holding it all together! The threads on the nut are ruined and the threads on the flywheel are a little bunged up on the end. Just enough that I can't get my new 5/8 18 nylock nut started. I need a thread chaser to clean it up. I have a friend who may have one, otherwise, I guess I'll have to take the engine to a machine shop and have somebody do it for me. The drive shaft is now a little thinner where it was spinning in the hub and the hole has been rounded or rather ovaled out. The drive cup and plate don't look that bad, I'm not sure what should be replaced.
How do I get the drive shaft out? Do I work from under the tractor, or do I take some sheet metal off and work from the top?
Thanks.

The tunnel cover on the narrow frames can't be removed, you have to remove the drive shaft from underneath. If the drive shaft has been in there for 40 years its going to be a major PITA to get it out. The easiest thing to do is to stand the tractor up on end and work on it that way. Just make sure you tie up the front end so it wont fall over, I use a chain fall but even a good piece of rope will work.

That is the way I do it also.A lot easier and dirt don't fall on your face.Are the threads on the crankshaft damaged?A machine shop is a good choice to get that done if you don't have the right tools.I have a drive cup in good shape,let me know

I recently put new parts in the drivetrain, and had the shaft redone on my 105.


I also put the tractor on it side, once I got the motor out. :ThumbsUp:

Another way is to support the tractor with jackstands under the footrests, disconnect the brake and hydro linkage, and pull the rearend out of the tractor with the driveshaft attached. Then you can fix the driveshaft, the trunion slot, and the cork gasket, and adjust the brakes very easily. If you turn it on its side or on end without draining the rear you'll lose a bunch of Hytran out of the breather.

Also, don't use a nylock nut- the insert will probably melt from the heat. It's not necessary anyway, a properly torqued OEM nut will not back off.

The damaged nut is an expanding lock nut. I bought the nylock figuring that heat would not such an issue in this location. Which brings me to my next question. How do I keep the engine from turning when I torque this nut?

Here's some pictures.
Drive cup.
http://i115.photobucket.com/albums/n...5/DSC06603.jpg
Drive plate
http://i115.photobucket.com/albums/n...5/DSC06606.jpg
http://i115.photobucket.com/albums/n...5/DSC06605.jpg
Drive shaft
http://i115.photobucket.com/albums/n...5/DSC06596.jpg
http://i115.photobucket.com/albums/n...5/DSC06595.jpg
The nut that had come loose. First is the damaged threads.
http://i115.photobucket.com/albums/n...5/DSC06600.jpg
http://i115.photobucket.com/albums/n...5/DSC06598.jpg
The threads on the shaft. Only the first one or two are kinda rounded over from the loose nut rolling around in there. I think they could easily be cleaned up if I had the right size die.
http://i115.photobucket.com/albums/n...5/DSC06602.jpg

I am assuming all these parts should be replaced. It is tempting to simply fix up those threads and put everything back together with a 1/4" bolt instead of the dowel.
If nothing else, at least I was able to clean 43 years of grass, dirt, and oil out of a few nooks and crannies.

I would not just put that all back together. A 1/4" bolt is not acceptable there. The crank will be fine, but you need a new (correct) nut, the driveshaft is shot, the slotted coupler needs welding and re-machining at a minimum, and the drive cup would also need to have some material added with a TIG welder and then be re-machined.

I borrowed the die and tap and fixed the threads on the shaft and the nut. Yes, I do need new parts. I'll have to do some shopping.

I know what your going through. I am into the same project+ from a guy that thought more weld is better. And with the driveshaft being out of balance from the poor welding job, it has done damage to the crankshaft and bearings.

What a mess!!! How can you even get all that apart?

I unbolted the front and rear of the driveshaft. Moved the engine enough to wiggle the whole assembly out in one piece. Still have to cut the driveshaft to get the one shield off of it. There is no hydro static cooling fan on the shaft either so that helped. Will be a lot easier now I have all the correct parts.

The Horror ....... some people should not be allowed to touch a welder

I got a new shaft, cup and plate today from darkminion_17. Just have to get one of those 1/4" pins and I should be able to get my tractor back together.

Steve,
Thanks for stopping by.It was great to meet you!

Lew,
You had all new parts but no pins. Steve I have 1 for you. Send me your address.
Mike

Mike.
I used the last one I had.Time to restock.Where did you get yours?

Mike, PM sent. Lew, nice to meet you. Thanks to both of you.

Lew,
I've had them in my tool box for years. I only have 2 left but are 2" instead of 1 1/2. I think McMaster carr should have them.


Steve,
I'll try to get that mailed to you today.
Mike

I just ordered the pins from McMaster-Carr. 1/4" x 1 1/2" alloy steel. I had to buy a bag of 50 so I will be happy to share with you guys. Lew, I have your address and Mike, if you sent the one you offered already, I will send to the return address. If you have not sent it yet, PM your address.
I had a friend at work weld up the slightly worn drive plate that I git from Lew. After a little file and drill work, it will be good as new.
The old drive shaft is out. I used my come along to lift the front of the tractor.
http://i115.photobucket.com/albums/n...5/DSC06608.jpg

I bolted the new drive cup on yesterday. I made this tool that bolts to the drive cup to keep the engine from turning when I tightened the bolt.

http://i115.photobucket.com/albums/n...0624111828.jpg
http://i115.photobucket.com/albums/n...0624111826.jpg

Does anybody know the proper torque for this bolt?
As soon as I have a drive pin, I should be able to put everything back together. Hopefully it will go back together as easily as it came apart.
Thanks again to all who have helped out.

Torque for the flywheel retaining nut would be 50-60 lb/ft.

Here's the link to the Kohler service manual.
It will have all your spec numbers and torque values:
http://www.kohlerengines.com/onlinec...df/tp_2379.pdf

Steve,
I mailed it out first class mail yesterday.
Mike

Thanks. :)

I got it back together today. Hopefully the drivetrain will be ok for another 40 years or so. Thanks to all who helped me out. I would have been lost without your help.

Steve,Is that the same GG that had the orange 1969 Z28? Also your welcome.

I didn't see him on Saturday and I am on vacation this week. I'll see the GG that I know next week.
It went back together pretty quickly. I was surprised that I remembered how it all came apart. This old tractor is definitely easier to take apart and put back together than my old truck. I'm gonna have to get another one some time and restore it. These machines are fun to play with.