Cub Cadet 123: head differences, damaged bore, hydrostatic leak

[knucklescraper]

darkminion_17,

Agreed, shorter spaces are necessary. I worked out the necessary sizes earlier today. The current spacers are 0.716" long (~23/32"). The two suporting the thicker plate will need to be ~1/4" shorter and the three under the gas tank will need to be ~3/8" shorter. I'll do some shopping.

ironman,
Thanks for the photos. Those are some beautiful tractors. The head you labeled 4th gen is the one I mounted to the K301A engine that I just put on the tractor. I bought that engine (with that head) from somenone on Craigslist earlier this month so I had no idea if it was the proper head. I'll continue with that head under the assumption that a 4th gen design is an improvement over a 3rd gen design. Maybe moving the spark plug provides more efficient combustion. I'm curious what benefit the studs/spacers add.

After I figured out the modifications I'd need for the baffle (thin plate) and shroud (thicker plate) and spacers earlier this afternoon, I then went ahead and split the tractor in preparation for finding the hydraulic leak.

I had some trouble getting the cotter pin out of the brake linkage rod. But that was nothing compared to the trouble I had trying to pull the tractor halves apart. I didn't have very good chucks under the front wheels so I kept dragging the whole tractor back every time I yanked on the rear. I was also using jacks and jack stands trying to shift the weight off the rear. But that usually raised the rear too.

There is a pin in the tow bar release lever that got caught on a nut on top of the hyrdo unit. I marked the nut up a bit before I noticed. Younger me would have just kept yanking and driven the pin into the hydraulic tube behind it. Even so, I came close to doing just that. I eventually had some arrangement of jacks and jackstands that had allowed the proper clearance. I separated the tractor by sitting on the ground behind rear, putting my feet on the frame and yanking on the rear axles. I had to be quite careful because the drawbar was aimed at a sensitive part of my anatomy.

Tomorrow's plan is to clean off the leaking hydraulic oil and try to find its source.
Once I find it, I probably have to remove the hydro unit to replace a seal or gasket. Is it possible to do that without draining the hydraulic fluid? Maybe by rotating the whole rear end 90 degrees upward from its normal orientation so the oil drains down into the differential housing and out of the hydro? That's what I'm thinkiing of trying anyway.

By the way, my tractor serial number 193356. Does that mean anything?

It's already tomorrow. TIme for bed.

[finsruskw]

That number means it was built in March of 1967

[West Valley G]

Glad you got the tractor split. Like I said it's not too ominous. I guess
maybe I should have given a description of ominous
Just think how easy it will be next time. I promise.

Ken

[knucklescraper]

West Valley G,

You called it. I think the leak is coming from that cork gasket. It is seeping very slowly (now that I want it to leak).


Back on the head and spacer issue...
I was looking at that again yesterday. I may have created my own problem.
Before I installed the head, I had watched an online video in which the guy used the stackup shown in the sketch "current hardware stackup" in the attached pdf file. So that's what I did.

Question: Do you guys that have heads with studs use a double nut stackup (nut - spacer - nut)?

It is probably not an accident that the spacer height is the same as the distance from the boss to the top of the fin. So now I'm thinking maybe the correct hardware stackup is what I sketeched in "solution #2". I only wonder why Kohler wouldn't have simply changed the boss head height to bring it even with the top of the fins?

EDIT: I think the pdf file was too large and it didn't upload the first time. I reduced its file size (and its quality) and re-uploaded it. I also attached a photo of the sketch. I don't know which is easier to read.

[ironman]

My humble suggestion is that you use the head that uses bolts, not studs, such as the attached pictures of my spare engine.
There is no advantage to what you are trying to do for all the angst that you are going through over studs and spacers.
What I have pictured has been working for 50 years. "Go with the flow!"

[finsruskw]

Dry the area well and then powder it all down w/talcom powder or maybe even flour and wait a while.
The leak will wet the powder and lead you right to where it is coming from.

[knucklescraper]

Replaced the cork gasket between hydro and differenntial hosuing.
Recoupled tractor halves.
Modified the baffle plates and went with hardware stackup "solution #2" described earlier for the time being. May revisit in the future.
Engine runs. Hydraulic leak gone after 1/2 hour of running.

Thank you everyone for your help!

[West Valley G]

I so like a love story with a happy ending. Or in this case a happy
middle more than likely. Well done.

Ken