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CELLARDWELLER

720 Transmission Problem

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CELLARDWELLER

I just purchased a 720 in good running condition but the transmission seems to get stuck in reverse after shifting it forward to reverse, then back forward... It will stay in reverse according to the guy that sold it.... Any thoughts on where to start looking? I have the shop manuals and can handle this myself. I'm just looking to see where a common problem may be, or save me some time.

I have a 185, and I want this to be a mini version. Thanks for any help..

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D-17_Dave

You will have a linkage problem or a serious problem inside the hydrostatic transmission pump section.

If it's inside the pump, your better off replacing the whole hydrostat section with a used one.

There are several possibilities inside the dash in the linkage for it to bind from age. Basically you'll need to remove the lower dash cover and look for a bind in the mechanism. It's likely the cross shaft that the hydro control handle rides on. It has no means of service to be oiled or greased and they bind up hard from not fully stroking the control to full reverse very often. I cut a groove in my control arm sleeve and drilled it for a grease zerk. While your in there you'll need to make sure the tension spring isn't broken as they often are and that the neoprene bushings (2)are not hardened and destroyed in the linkage. Cheep and easy replacement while your into it.

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MysTiK

Different tractor, also hydro - my 716H hydro stick broke the pin at bottom of stick. It was like a broken weld, and I welded it. fixed.

While broken, the stick could not move the linkage.

The linkage was effectively disconnected - stick moves, no grab due to broke pin.

The hydro is then free to do what it wants - the springs etc throw the linkage into reverse - by default - and it's full reverse.

The actual linkage starts with what looks like a miniaturization of the stick itself.

also - after fix, a neutral adjustment might be needed - this is in manuals - it's called forward or reverse "creep" - tractor moves slightly in neutral. but that's after you fix the stick and/or linkage issue. Range of stick travel, and hydro response can be affected - it's also fixed thru doing a neutral adjust.

my thread, my tractor here:

http://www.simpletractors.com/club2/topic.asp?TOPIC_ID=121508&SearchTerms=hydro,bust

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