Cub 123 transmission area sprang a leak!
 

I have not been on the forum for quite some time, but my butt hasn't been in the seat of my Cub 123 for a long time, either. Well, today was the day...... and it was short-lived.
I always keep the #1 tiller on this GT, and I got it out today to play in the garden. Made about 3 passes around a section of the garden when I heard a different, grinding kind of noise. I shut off the tractor, then noticed transmission fluid pouring out of the rear end in the area of the transmission oil filter. I poked around that area and found a loose bolt, a washer was on the ground. No nut found anywhere. I have never really done anything in this area of the tractor, except for cleaning the rear end and replacing the transmission fluid and filter when I acquired this GT 10-15 years ago, so I don't know much about it.... BUT.... I have a service manual and a parts manual! Looking at both, I believe there is something related to the flexible coupling disc and the related bolts (item 50 in the parts manual). There was a worn-through slice in the top side of the oil filter.
Luckily I have a Troy-Bilt Horse and a Wheel Horse C160 w/tiller (and even a little 4-stroke Mantis!) as backup.
So, I guess I get to split the tractor and fix it!

Any tips or pointers????

Sounds like the Flex Disc Coupler let loose. Time to jack up the tractor, and take a look. Let us know what you find.

Thank you... I sure will.

Got the 123 split apart…. That wasn’t too bad. Found that one of the bolts on the pump drive shaft/flex disk had loosened over time, wore it’s way through the flex disk, fell out (that’s what I found on the ground), and that part of the shaft dropped down enough to chew a hole in the upper side of the oil filter.
I have ordered a new flex disk (from CCS), and Napa has a new filter coming for me. While I am waiting, I will go by TSC and get some stainless bolts and some nylock nuts for putting it back together.

Looks like you stopped the tractor in the "nick of time" before carnage took place. We have seen photos of catastrophic failures before. Glad to see you caught before a major parts destruction.

:IH Trusted Hand:

Thank you... I feel very fortunate.

For the engine-end of the drive shaft, can you suggest where I might find a dowel pin? IH - 19837- R1 in my manual. One end of the dowel I have is sheared off at the shaft.

I think this is what you're after: https://ccspecialties.org/pics/drivepinlarge.jpg

From this website: https://ccspecialties.org/clutch_driveline_rearend.html

Do a "CTRL+F" and type in "IH-19837-R1" to find it. They have .001 and .002 size over pins too if yours is a little rounded out.

Alternatively, if you can get the bits of it together for a measurement you can probably get a suitable replacement at McMaster-Carr.

Thank you so much. I have sent CCS an email asking if they can throw in a dowel pin, and we'll arrange payment.... (hoping it doesn't require a separate $10 shipping fee).

Oh!!! While cleaning the 123 I FOUND the nut! (No, I didn't look in the mirror.... )...... not going to use it, but I found it..... it was laying in the oil/dirt on the frame rail.

Looks like it's time to break out power washer for a little house cleaning in there while you are at it.

Check the front coupler while you are at it as well.