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#1 Nategracie808 OFFLINE  


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Posted May 05, 2013 - 01:48 PM

Hi Everyone,


I am for all intents and purposes new to the forum. I bid you all good day.


I have a 1968 Jacobsen (Ford) Super Chief 120 that runs flawlessly. It has the 2 stage thrower, the dozer blade, the trip blade and the mower deck, original wheel weights and chains and 6 full sets of tires. My problem is that the hydrostatic is weak. I have cleaned the filter and replaced the fluid. The tractor can barely move itself across the grass. I love this little tractor and was wondering if there is a way to fix.


I have lifted it off the ground and found that when one wheel is turned, the other goes in the opposite direction, I have not found the shafts spinning and the wheels not moving, all the pulleys seem to be doing their job. When the lever is pushed all the way forward or backward it sounds like there is a loose nut inside the pump rattling around. If the lever is only pushed forward a bit, then the tractor will move slowly but weakly and the awful noise goes away. This seems to happen in either direction but I must say that reverse does seem a bit stronger.


My question is about the pump/transmission. Can these be rebuilt with off the shelf parts? Can a local shop do it? Would it be worth doing these things to it? I am afraid I just don't know enough about the transmissions to make a proper decision without some of the experts on this forum. Anything you folks can recommend would be greatly appreciated.


I have also done a few searches and not found the answers I am looking for in the forums or the manuals. :)





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#2 KennyP ONLINE  



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Posted May 05, 2013 - 02:28 PM

Welcome to the forum! Are you sure it is full of fluid? Have you changed the fluid out?

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#3 olcowhand ONLINE  


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Posted May 05, 2013 - 02:40 PM

There should be a knob just below the seat on the right of the tunnel cover plate.  This knob must be rotated clockwise till it stops for the hydro to drive.  If it is not full clockwise, fluid pressure is being bypassed.  Turning full counterclockwise is for pulling/pushing the tractor with engine not running.  If it is slightly off full clockwise lock position, it would try to move, but not be able to with force.  Check this knob first, then we can go from there.  As far as the counter rotating wheels when off the ground, this is normal, as it's the differential doing what it is supposed to do.

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#4 hamman OFFLINE  


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Posted May 05, 2013 - 02:42 PM

Nategracie, welcome to the forum. My 72 Superchief 1200 hydro has the knob to release the transmission to be able to push it. Does yours have that? On ours it is located to the front of the seat and has to be turned all the way to the right to make it move. Not sure of your model. I could only find one picture of a tractor possibly like yours and it looks like the hydro knob is the same place as ours. Maybe try turning that right or left to make sure it is locked in for the tractor to move. Hope this helps. Thanks. Roger.

#5 superaben OFFLINE  

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Posted May 05, 2013 - 03:45 PM

Welcome to the forum!  Contrary to what you might think, although hydro units are complex, there's only a few things that usually go bad.  Its probably something simple, like what Daniel and Roger have mentioned. 


I've worked on a few hydros, but I'm not too familiar with who was the manufacturer of Jacobsen's hydro unit.  Who made it for them?


Ben W.

#6 JDBrian OFFLINE  


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Posted May 05, 2013 - 04:03 PM

Welcome to GTTalk. Is it possible you have a linkage problem and the speed control is not able to fully activate the hydro? Just thought I'd throw that in the mix. 

#7 Nategracie808 OFFLINE  


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Posted May 05, 2013 - 04:48 PM

Wow, I like this forum.....thanks for all the fast replies!


I have checked the fluid and changed it

The knob is turned fully clockwise

I can see the belt turning the pump quite fast, but no movement from the tractor.

I am unsure of the hydro unit make.


Keep the questions coming, I like the brainstorming you guys are helping me with! :)


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Posted May 05, 2013 - 05:41 PM

:welcometogttalk: , and :wewantpics:

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#9 Nategracie808 OFFLINE  


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Posted May 05, 2013 - 06:39 PM

Here is a vid of said problems! KC9KAS thanks for the encouragment!