Baffled newb - need help - D1105 runs up to full throttle and wont idle down

[North Idaho Wolfman]

Have the hydraulics not been working?

The tabs that are broken are the tabs for the drive for the hydraulic pump.
Those being broken should have no bearing on it idling, but then again anything is possible when parts get broken.
The reason the tabs are broken are because there is either a bad pump or the pump is dead headed caused by a fault in the system, like a blocked relief valve or an otherwise damaged or altered system thus not allowing the pump to spin.

It sounds like the pump or system isn't working like it should, it does require a lot of HP to run the pump when it's loaded, but in a neutral state it free flows.

Check all the controls for a control that is engaged, thus causing the system to be under a load.

 

[Flatiron71]

Wolfman - thanks for the reply. There's a snap ring on the far end of the governor shaft where the tabs broke off that hold the shaft in place. It got broken along with the tabs which allowed the shaft to slide back and forth in the housing. When the fly weights would move the thrust washer it would just slide the shaft instead of moving the governor arm linkage therefore allowing the engine to rev up to full throttle.

I pulled the hydraulic pump off and pulled it apart - it spun freely and had no debris of any kind inside. I looks really clean in there which leads me to believe something dead headed causing it to lock up and the unfortunate chain reaction.
As it is I will still have to get a new pump because the outside seal got chewed up by the broken tabs from the governor shaft tumbling around in there between the pump face and the roller bearing.
Next step is to try to figure out what may have dead headed. That pump only supplies high pressure to the steering ram and the lift ram inside the transmission case. Man this is getting deep......
Any more input would be greatly appreciated

.

 

[Flatiron71]

Can anyone tell me what this adjustment knob is (see pic below) for on the top of the transmission? It goes into the back where the hydraulic ram is that is used to lift the mower deck and is a suspect of what may have dead headed the pump. The knob is adjusted all the way in, clockwise to its stop.
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