cat 955 H wont move and hydraulic dont work

[sawmilleng]

When you say "the hydraulics wont work do you mean the loader hydraulics? Doesn't the loader pump run off the front of the engine?

Jon.

 

[randy lee hoeft]

i dont know i think it runs transmission, and hydraulics

 

[sawmilleng]

From the drawing AllDodge has posted it looks like the converter is somehow attached to the engine flywheel with either a center spline or maybe the large gear on the converter slides into a corresponding internal gear on the flywheel.
In any event, if there is no hydraulic pressure in the transmission, it suggests to me that the outside of the torque isn't turning since that is what drives the trans pump, which is also shown on the drawing.

AllDodge or Nige, if this sounds reasonable, what is between the engine flywheel and the torque converter? How is the torque driven?

I'm guessing there must be an inspection plate on the bell housing somewhere where a guy could have a look and see if the torque is turning with the engine.

I suppose another theory could be that if the torque is turning, but the trans pump is shot or stripped a drive gear and isn't pumping oil. That would equal no trans oil pressure and no action in the transmission.

Jon.

 

[.RC.]

I wonder if the setup is like my 922 loader. The transmission pump and the hydraulic pump is driven off the same shaft on the top rear of the torque converter. The converter/transmission unit bolts direct to the flywheel housing.

 

[sawmilleng]

.RC., now that you mention it, there IS another gear in the drawing that AllDodge posted that engages the same gear that the trans pump drives off of. Its on the top of the page and drives to something that is just barely visible on the top of the drawing. Might that be the drive to a hydraulic pump?

So if Randy isn't seeing trans pressure AND cannot move the loader lift or bucket tilt then the torque converter is likely not turning.

Either way, it looks like the housing containing the torque needs to be opened up.

Jon.

 

[AllDodge]

I'm not very familiar with the H model, but I'm thinking the upper gear in the post may be where the starter engages

 

[kshansen]

I'm not very familiar with the H model, but I'm thinking the upper gear in the post may be where the starter engages

I'm also not familiar with the 955 H but going by all the Cat equipment I am familiar with if this machine is a direct electric starting machine I would expect the starter to engage the flywheel to crank the engine. Then the converter would be driven by the splines on the conveter where I have put the red arrow, there would be matching splines in the flywheel.

 

[kshansen]

The upper gear I have colored orange in the picture below would be the one that drives the transmission pump. There appears to be an idler gear between it and the gear on the converter. The small pump down near the bottom is a scavenger pump.

 

[randy lee hoeft]

Thanks guys i will check it out