Cub 154 Fails to Proceed

[bookman51]

Well, I finally got my 1969 Cub 154 all started and going. I have a fellow who said he would buy it. Well, I went out late this afternoon and started it and mowed with it about 20 minutes just to check it out before selling it...and began to wonder why I was selling it. The throttle lever need a tightened and the clutch seemed a little quick but the gears were not grinding. Everything was going great. Then suddenly it was failing to proceed. The engine was still running, as was the mower, and there seemed to be some grinding noise under me.

I shut it off and pulled it into my shop. I took the frame cover off to eyeball the drive train. Nothing jumped out at me but I don't have trained eye for these things.

The I jacked up the rear end, put it in gear and turned a rear wheel. Depending the gear, sometimes the clutch would turn and sometimes not. I let the tractor down, and put a pipe wrench on the main clutch shaft, put the tractor in gear, and turned the shaft. The wheels did not turn.

Now there is a pin the shaft up near the flywheel right behind the engine. That pin is okay.

How bad and am I going to have get a real mechanic to fix it???? I do not think this old girl wants to get sold. Thanks in advance.

[outdoors4evr]

Don't panic. There is another pin toward the aft side of the driveshaft. Pretty common for these to wear and break. The pin can be replaced with a soft bolt (don't use a hardened grade 8 ) and a locknut. Grind off any excess length of the bolt.

[bookman51]

Thanks. I have the parts manual and service manual, and I am not finding a pin the the driveshaft in the clutch area. Can you be more specific as to location? The serial number of the tractors is 10325 (1969 model) if that is some help. Thanks again.

[Landreo]

Early 154s such as yours originally had a spiral, Spirol, pin connecting the driven disc or pressure plate to the transmission input shaft. No pins on the rear end of the driveshaft. Later models used a HARDENED Allen head bolt. That is not a shear pin and needs to be at least a grade 5, better if grade 8.

If you have a broken spiral pin then replace with a 5/16 X 2 inch spiral pin. Do not use a split or roll pin. If your driven disc has been replaced at some time in the past then it will have that Allen head bolt connection.

[bookman51]

Thanks. It does not show in my parts book, but I went back to the local Case-IH dealer and it shows in their computer's parts book...as a part associated with the pressure plate. They had a spiral pin in stock. So I am going to try put it on this afternoon. Well into the 90s here so we will see how it goes. Kind of depends on how much room is available, how much more sheet metal I have to take off, if anyone has modified anything over the years, and how hot I get). Thanks for the great help.

[bookman51]

Next question (s). I looked at the service manual. Will I have to open up the front and slide the main shaft forward and move engine forward to get to the clutch in the rear? The service manual does not say so, but will I have to remove the sheet metal under the seat?

[bookman51]

I got it apart following the service manual. I had trouble getting the engine to slide ahead enough. The clutch plate looks good. The pressure plate assembly seems firmly attached. So I do not know what happened. Is it somehow possible for the main clutch shaft to slide far enough forward to the splines to come out of the disc assembly? Tomorrow I will reassemble it and see what happpens.

[wagonmaster]

Last year my 154 did the same thing and it had broken the center out of the clutch disc.

[mozer71]

This is totally interesting. The "grinding noise" was from under the seat, right?

[bookman51]

Wagonmaster, I thought you were on to something but the center of the clutch disc seems fine. The splines on it seem good when I slide it on to the drive shaft. I am having problems getting the engine to slide forward enough to get the drive shaft out or the clutch disc out. Any suggestions?

[bookman51]

This is totally interesting. The "grinding noise" was from under the seat, right?

Well, both the transmission and the clutch are in that area. I have the clutch pretty well taken apart, and I am finding nothing, but then I may not know what to look for. I am having problems getting the engine to slide forward enough to get the clutch plate off or the drive shaft out. Any suggestions? I am not seeing anything obviously loose or sheared, etc.

Unless someone comes up with better ideas, I may just put the tractor back together and see what happens. Obviously something is wrong, but I do not know what. The tractor stopped all of a sudden. Engine still running. Mower still running. Seemed some grinding in the clutch/transmission area. As I take it apart, everything seems fine, but I could be missing something.

[Landreo]

Not much in the clutch area that would do this and not be obvious. Did you try turning the drive shaft while in gear and see if the pressure plate turns without moving the wheels? If so, then likely the pin has sheared but the ends remained in place so it looks intact. How did you determine the pin is intact?

I would not pull the driveshaft if the shaft and clutch look intact. Other things to think about would be a broken iput shaft but unlikely or it is stuck in neutral. You should be able to feel gears sliding when moving the gear shift lever.

[bookman51]

Not much in the clutch area that would do this and not be obvious. Did you try turning the drive shaft while in gear and see if the pressure plate turns without moving the wheels? If so, then likely the pin has sheared but the ends remained in place so it looks intact. How did you determine the pin is intact?

I would not pull the driveshaft if the shaft and clutch look intact. Other things to think about would be a broken iput shaft but unlikely or it is stuck in neutral. You should be able to feel gears sliding when moving the gear shift lever.

I will do some checking but when I moved the pressure plate with the tractor in gear, the wheels do move in each gear. I can put in 1, 2, 3, or reverse and the wheels do move. I have not tried to get to the spiral pin behind the pressure point (yet) since I would have to take off the clutch retainer brake, which is kind of a pain to remove and put back on.

I can shift the gears so not stuck in neutral and when moving the pressure plate in each gear the wheels do move. Color me puzzled. I swear the tractor quit moving, the engine continued to run, and the mower continued to run. I also swear I engaged the clutch and tried different gears. I don't think it was all my imagination

I plan to work on it later today some more. Maybe I put something back together wrong a few years ago when I replaced the clutch retainer brake. I have not used it much since. I mowed with it about 20 minutes the other day before this happened. It sure acted like something suddenly sheared (and not the clutch slipping), but the pin in front up by the engine is okay. I took it out and inspected it. And moving the pressure plate in the back with the tractor in gear moves the tractor. When I put the clutch facing on the drive shaft, the splines on both seem to mesh and be okay.

Gotta be something though. Before I took the drive train apart, I had put a pipe wrench on the drive shaft and put the tractor in gear and the wheels would not move...and the clutch was engaged (clutch pedal not pushed in). I would think there are only so many things between the engine and the transmission that can go wrong, and that they should be obvious upon inspection (but I must be wrong...again!!).

I plan to start putting it back together today or tomorrow and see if find anything I missed. I had hoped to sell the tractor. The fellow was to come get it this morning, but now he has moved on, and I do not blame him. Thanks

[outdoors4evr]

Perhaps the rivets failed between the clutch hub and the clutch disc?
Use the same test, put the tractor in third gear and instead of turning the pressure plate or driveshaft, try rolling the tractor. This would put a load on the wheels and the engine would provide the resistance to see where it slips. Working properly, the engine fan would turn. Work your way from one end to the other and find what part is slipping.

[bookman51]

Perhaps the rivets failed between the clutch hub and the clutch disc?
Use the same test, put the tractor in third gear and instead of turning the pressure plate or driveshaft, try rolling the tractor. This would put a load on the wheels and the engine would provide the resistance to see where it slips. Working properly, the engine fan would turn. Work your way from one end to the other and find what part is slipping.

Thanks, I will give that a shot.